Finite Math Examples

$[\begin{array}{c} 1 & 2 & 7 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{array}] [\begin{array}{c} x \\ y \\ z \end{array}] = [\begin{array}{c} 12 \\ 11 \\ 17 \end{array}]$

Step 1

Multiply $[\begin{array}{c} 1 & 2 & 7 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{array}] [\begin{array}{c} x \\ y \\ z \end{array}]$ .

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Step 1.1

Two matrices can be multiplied if and only if the number of columns in the first matrix is equal to the number of rows in the second matrix. In this case, the first matrix is $3 \times 3$ and the second matrix is $3 \times 1$ .

Step 1.2

Multiply each row in the first matrix by each column in the second matrix.

$[\begin{array}{c} 1 x + 2 y + 7 z \\ 4 x + 5 y + 6 z \\ 7 x + 8 y + 9 z \end{array}] = [\begin{array}{c} 12 \\ 11 \\ 17 \end{array}]$

Step 1.3

Simplify each element of the matrix by multiplying out all the expressions.

$[\begin{array}{c} x + 2 y + 7 z \\ 4 x + 5 y + 6 z \\ 7 x + 8 y + 9 z \end{array}] = [\begin{array}{c} 12 \\ 11 \\ 17 \end{array}]$

Step 2

Write as a linear system of equations.

$x + 2 y + 7 z = 12$

$4 x + 5 y + 6 z = 11$

$7 x + 8 y + 9 z = 17$

Step 3

Solve the system of equations.

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Step 3.1

Move all terms not containing $x$ to the right side of the equation.

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Step 3.1.1

Subtract $2 y$ from both sides of the equation.

$x + 7 z = 12 - 2 y$

$4 x + 5 y + 6 z = 11$

$7 x + 8 y + 9 z = 17$

Step 3.1.2

Subtract $7 z$ from both sides of the equation.

$x = 12 - 2 y - 7 z$

$4 x + 5 y + 6 z = 11$

$7 x + 8 y + 9 z = 17$

$x = 12 - 2 y - 7 z$

$4 x + 5 y + 6 z = 11$

$7 x + 8 y + 9 z = 17$

Step 3.2

Replace all occurrences of $x$ with $12 - 2 y - 7 z$ in each equation.

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Step 3.2.1

Replace all occurrences of $x$ in $4 x + 5 y + 6 z = 11$ with $12 - 2 y - 7 z$ .

$4 (12 - 2 y - 7 z) + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2

Simplify the left side.

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Step 3.2.2.1

Simplify $4 (12 - 2 y - 7 z) + 5 y + 6 z$ .

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Step 3.2.2.1.1

Simplify each term.

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Step 3.2.2.1.1.1

Apply the distributive property.

$4 \cdot 12 + 4 (- 2 y) + 4 (- 7 z) + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2.1.1.2

Simplify.

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Step 3.2.2.1.1.2.1

Multiply $4$ by $12$ .

$48 + 4 (- 2 y) + 4 (- 7 z) + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2.1.1.2.2

Multiply $- 2$ by $4$ .

$48 - 8 y + 4 (- 7 z) + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2.1.1.2.3

Multiply $- 7$ by $4$ .

$48 - 8 y - 28 z + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

$48 - 8 y - 28 z + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

$48 - 8 y - 28 z + 5 y + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2.1.2

Simplify by adding terms.

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Step 3.2.2.1.2.1

Add $- 8 y$ and $5 y$ .

$48 - 3 y - 28 z + 6 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.2.1.2.2

Add $- 28 z$ and $6 z$ .

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$7 x + 8 y + 9 z = 17$

Step 3.2.3

Replace all occurrences of $x$ in $7 x + 8 y + 9 z = 17$ with $12 - 2 y - 7 z$ .

$7 (12 - 2 y - 7 z) + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4

Simplify the left side.

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Step 3.2.4.1

Simplify $7 (12 - 2 y - 7 z) + 8 y + 9 z$ .

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Step 3.2.4.1.1

Simplify each term.

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Step 3.2.4.1.1.1

Apply the distributive property.

$7 \cdot 12 + 7 (- 2 y) + 7 (- 7 z) + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4.1.1.2

Simplify.

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Step 3.2.4.1.1.2.1

Multiply $7$ by $12$ .

$84 + 7 (- 2 y) + 7 (- 7 z) + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4.1.1.2.2

Multiply $- 2$ by $7$ .

$84 - 14 y + 7 (- 7 z) + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4.1.1.2.3

Multiply $- 7$ by $7$ .

$84 - 14 y - 49 z + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 14 y - 49 z + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 14 y - 49 z + 8 y + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4.1.2

Simplify by adding terms.

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Step 3.2.4.1.2.1

Add $- 14 y$ and $8 y$ .

$84 - 6 y - 49 z + 9 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.2.4.1.2.2

Add $- 49 z$ and $9 z$ .

$84 - 6 y - 40 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 6 y - 40 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 6 y - 40 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 6 y - 40 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$84 - 6 y - 40 z = 17$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3

Solve for $y$ in $84 - 6 y - 40 z = 17$ .

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Step 3.3.1

Move all terms not containing $y$ to the right side of the equation.

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Step 3.3.1.1

Subtract $84$ from both sides of the equation.

$- 6 y - 40 z = 17 - 84$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.1.2

Add $40 z$ to both sides of the equation.

$- 6 y = 17 - 84 + 40 z$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.1.3

Subtract $84$ from $17$ .

$- 6 y = - 67 + 40 z$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$- 6 y = - 67 + 40 z$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2

Divide each term in $- 6 y = - 67 + 40 z$ by $- 6$ and simplify.

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Step 3.3.2.1

Divide each term in $- 6 y = - 67 + 40 z$ by $- 6$ .

$\frac{- 6 y}{- 6} = \frac{- 67}{- 6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.2

Simplify the left side.

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Step 3.3.2.2.1

Cancel the common factor of $- 6$ .

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Step 3.3.2.2.1.1

Cancel the common factor.

$\frac{- 6 y}{- 6} = \frac{- 67}{- 6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.2.1.2

Divide $y$ by $1$ .

$y = \frac{- 67}{- 6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{- 67}{- 6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{- 67}{- 6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3

Simplify the right side.

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Step 3.3.2.3.1

Simplify each term.

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Step 3.3.2.3.1.1

Dividing two negative values results in a positive value.

$y = \frac{67}{6} + \frac{40 z}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3.1.2

Cancel the common factor of $40$ and $- 6$ .

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Step 3.3.2.3.1.2.1

Factor $2$ out of $40 z$ .

$y = \frac{67}{6} + \frac{2 (20 z)}{- 6}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3.1.2.2

Cancel the common factors.

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Step 3.3.2.3.1.2.2.1

Factor $2$ out of $- 6$ .

$y = \frac{67}{6} + \frac{2 (20 z)}{2 (- 3)}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3.1.2.2.2

Cancel the common factor.

$y = \frac{67}{6} + \frac{2 (20 z)}{2 \cdot - 3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3.1.2.2.3

Rewrite the expression.

$y = \frac{67}{6} + \frac{20 z}{- 3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} + \frac{20 z}{- 3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} + \frac{20 z}{- 3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.3.2.3.1.3

Move the negative in front of the fraction.

$y = \frac{67}{6} - \frac{20 z}{3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} - \frac{20 z}{3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} - \frac{20 z}{3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} - \frac{20 z}{3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

$y = \frac{67}{6} - \frac{20 z}{3}$

$48 - 3 y - 22 z = 11$

$x = 12 - 2 y - 7 z$

Step 3.4

Replace all occurrences of $y$ with $\frac{67}{6} - \frac{20 z}{3}$ in each equation.

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Step 3.4.1

Replace all occurrences of $y$ in $48 - 3 y - 22 z = 11$ with $\frac{67}{6} - \frac{20 z}{3}$ .

$48 - 3 (\frac{67}{6} - \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2

Simplify the left side.

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Step 3.4.2.1

Simplify $48 - 3 (\frac{67}{6} - \frac{20 z}{3}) - 22 z$ .

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Step 3.4.2.1.1

Simplify each term.

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Step 3.4.2.1.1.1

Apply the distributive property.

$48 - 3 (\frac{67}{6}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.2

Cancel the common factor of $3$ .

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Step 3.4.2.1.1.2.1

Factor $3$ out of $- 3$ .

$48 + 3 (- 1) (\frac{67}{6}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.2.2

Factor $3$ out of $6$ .

$48 + 3 \cdot (- 1 \frac{67}{3 \cdot 2}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.2.3

Cancel the common factor.

$48 + 3 \cdot (- 1 \frac{67}{3 \cdot 2}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.2.4

Rewrite the expression.

$48 - 1 (\frac{67}{2}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$48 - 1 (\frac{67}{2}) - 3 (- \frac{20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.3

Cancel the common factor of $3$ .

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Step 3.4.2.1.1.3.1

Move the leading negative in $- \frac{20 z}{3}$ into the numerator.

$48 - 1 (\frac{67}{2}) - 3 \frac{- 20 z}{3} - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.3.2

Factor $3$ out of $- 3$ .

$48 - 1 (\frac{67}{2}) + 3 (- 1) (\frac{- 20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.3.3

Cancel the common factor.

$48 - 1 (\frac{67}{2}) + 3 \cdot (- 1 \frac{- 20 z}{3}) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.3.4

Rewrite the expression.

$48 - 1 (\frac{67}{2}) - 1 (- 20 z) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$48 - 1 (\frac{67}{2}) - 1 (- 20 z) - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.4

Multiply $- 20$ by $- 1$ .

$48 - 1 (\frac{67}{2}) + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.1.5

Rewrite $- 1 (\frac{67}{2})$ as $- (\frac{67}{2})$ .

$48 - \frac{67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$48 - \frac{67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.2

To write $48$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$48 \cdot \frac{2}{2} - \frac{67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.3

Combine $48$ and $\frac{2}{2}$ .

$\frac{48 \cdot 2}{2} - \frac{67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.4

Combine the numerators over the common denominator.

$\frac{48 \cdot 2 - 67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.5

Simplify the numerator.

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Step 3.4.2.1.5.1

Multiply $48$ by $2$ .

$\frac{96 - 67}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.5.2

Subtract $67$ from $96$ .

$\frac{29}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$\frac{29}{2} + 20 z - 22 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.2.1.6

Subtract $22 z$ from $20 z$ .

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 2 y - 7 z$

Step 3.4.3

Replace all occurrences of $y$ in $x = 12 - 2 y - 7 z$ with $\frac{67}{6} - \frac{20 z}{3}$ .

$x = 12 - 2 (\frac{67}{6} - \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4

Simplify the right side.

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Step 3.4.4.1

Simplify $12 - 2 (\frac{67}{6} - \frac{20 z}{3}) - 7 z$ .

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Step 3.4.4.1.1

Simplify each term.

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Step 3.4.4.1.1.1

Apply the distributive property.

$x = 12 - 2 (\frac{67}{6}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.2

Cancel the common factor of $2$ .

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Step 3.4.4.1.1.2.1

Factor $2$ out of $- 2$ .

$x = 12 + 2 (- 1) (\frac{67}{6}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.2.2

Factor $2$ out of $6$ .

$x = 12 + 2 \cdot (- 1 \frac{67}{2 \cdot 3}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.2.3

Cancel the common factor.

$x = 12 + 2 \cdot (- 1 \frac{67}{2 \cdot 3}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.2.4

Rewrite the expression.

$x = 12 - 1 (\frac{67}{3}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 1 (\frac{67}{3}) - 2 (- \frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.3

Multiply $- 2 (- \frac{20 z}{3})$ .

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Step 3.4.4.1.1.3.1

Multiply $- 1$ by $- 2$ .

$x = 12 - 1 (\frac{67}{3}) + 2 (\frac{20 z}{3}) - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.3.2

Combine $2$ and $\frac{20 z}{3}$ .

$x = 12 - 1 (\frac{67}{3}) + \frac{2 (20 z)}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.3.3

Multiply $20$ by $2$ .

$x = 12 - 1 (\frac{67}{3}) + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - 1 (\frac{67}{3}) + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.1.4

Rewrite $- 1 (\frac{67}{3})$ as $- (\frac{67}{3})$ .

$x = 12 - \frac{67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = 12 - \frac{67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.2

To write $12$ as a fraction with a common denominator, multiply by $\frac{3}{3}$ .

$x = 12 \cdot \frac{3}{3} - \frac{67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.3

Combine $12$ and $\frac{3}{3}$ .

$x = \frac{12 \cdot 3}{3} - \frac{67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.4

Combine the numerators over the common denominator.

$x = \frac{12 \cdot 3 - 67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.5

Simplify the numerator.

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Step 3.4.4.1.5.1

Multiply $12$ by $3$ .

$x = \frac{36 - 67}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.5.2

Subtract $67$ from $36$ .

$x = \frac{- 31}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = \frac{- 31}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.6

Move the negative in front of the fraction.

$x = - \frac{31}{3} + \frac{40 z}{3} - 7 z$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.7

To write $- 7 z$ as a fraction with a common denominator, multiply by $\frac{3}{3}$ .

$x = - \frac{31}{3} + \frac{40 z}{3} - 7 z \cdot \frac{3}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.8

Combine $- 7 z$ and $\frac{3}{3}$ .

$x = - \frac{31}{3} + \frac{40 z}{3} + \frac{- 7 z \cdot 3}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.9

Combine the numerators over the common denominator.

$x = - \frac{31}{3} + \frac{40 z - 7 z \cdot 3}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.10

Combine the numerators over the common denominator.

$x = \frac{- 31 + 40 z - 7 z \cdot 3}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.11

Multiply $3$ by $- 7$ .

$x = \frac{- 31 + 40 z - 21 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.12

Subtract $21 z$ from $40 z$ .

$x = \frac{- 31 + 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.13

Rewrite $- 31$ as $- 1 (31)$ .

$x = \frac{- 1 \cdot 31 + 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.14

Factor $- 1$ out of $19 z$ .

$x = \frac{- 1 \cdot 31 - (- 19 z)}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.15

Factor $- 1$ out of $- 1 (31) - (- 19 z)$ .

$x = \frac{- 1 (31 - 19 z)}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.4.4.1.16

Move the negative in front of the fraction.

$x = - \frac{31 - 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{31 - 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{31 - 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{31 - 19 z}{3}$

$\frac{29}{2} - 2 z = 11$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5

Solve for $z$ in $\frac{29}{2} - 2 z = 11$ .

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Step 3.5.1

Move all terms not containing $z$ to the right side of the equation.

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Step 3.5.1.1

Subtract $\frac{29}{2}$ from both sides of the equation.

$- 2 z = 11 - \frac{29}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.2

To write $11$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$- 2 z = 11 \cdot \frac{2}{2} - \frac{29}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.3

Combine $11$ and $\frac{2}{2}$ .

$- 2 z = \frac{11 \cdot 2}{2} - \frac{29}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.4

Combine the numerators over the common denominator.

$- 2 z = \frac{11 \cdot 2 - 29}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.5

Simplify the numerator.

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Step 3.5.1.5.1

Multiply $11$ by $2$ .

$- 2 z = \frac{22 - 29}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.5.2

Subtract $29$ from $22$ .

$- 2 z = \frac{- 7}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$- 2 z = \frac{- 7}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.1.6

Move the negative in front of the fraction.

$- 2 z = - \frac{7}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$- 2 z = - \frac{7}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2

Divide each term in $- 2 z = - \frac{7}{2}$ by $- 2$ and simplify.

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Step 3.5.2.1

Divide each term in $- 2 z = - \frac{7}{2}$ by $- 2$ .

$\frac{- 2 z}{- 2} = \frac{- \frac{7}{2}}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.2

Simplify the left side.

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Step 3.5.2.2.1

Cancel the common factor of $- 2$ .

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Step 3.5.2.2.1.1

Cancel the common factor.

$\frac{- 2 z}{- 2} = \frac{- \frac{7}{2}}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.2.1.2

Divide $z$ by $1$ .

$z = \frac{- \frac{7}{2}}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{- \frac{7}{2}}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{- \frac{7}{2}}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3

Simplify the right side.

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Step 3.5.2.3.1

Multiply the numerator by the reciprocal of the denominator.

$z = - \frac{7}{2} \cdot \frac{1}{- 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3.2

Move the negative in front of the fraction.

$z = - \frac{7}{2} \cdot (- \frac{1}{2})$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3.3

Multiply $- \frac{7}{2} (- \frac{1}{2})$ .

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Step 3.5.2.3.3.1

Multiply $- 1$ by $- 1$ .

$z = 1 (\frac{7}{2}) \cdot \frac{1}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3.3.2

Multiply $\frac{7}{2}$ by $1$ .

$z = \frac{7}{2} \cdot \frac{1}{2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3.3.3

Multiply $\frac{7}{2}$ by $\frac{1}{2}$ .

$z = \frac{7}{2 \cdot 2}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.5.2.3.3.4

Multiply $2$ by $2$ .

$z = \frac{7}{4}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{7}{4}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{7}{4}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{7}{4}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$z = \frac{7}{4}$

$x = - \frac{31 - 19 z}{3}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6

Replace all occurrences of $z$ with $\frac{7}{4}$ in each equation.

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Step 3.6.1

Replace all occurrences of $z$ in $x = - \frac{31 - 19 z}{3}$ with $\frac{7}{4}$ .

$x = - \frac{31 - 19 (\frac{7}{4})}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2

Simplify the right side.

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Step 3.6.2.1

Simplify $- \frac{31 - 19 (\frac{7}{4})}{3}$ .

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Step 3.6.2.1.1

Simplify the numerator.

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Step 3.6.2.1.1.1

Multiply $- 19 (\frac{7}{4})$ .

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Step 3.6.2.1.1.1.1

Combine $- 19$ and $\frac{7}{4}$ .

$x = - \frac{31 + \frac{- 19 \cdot 7}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.1.2

Multiply $- 19$ by $7$ .

$x = - \frac{31 + \frac{- 133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{31 + \frac{- 133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.2

Move the negative in front of the fraction.

$x = - \frac{31 - \frac{133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.3

To write $31$ as a fraction with a common denominator, multiply by $\frac{4}{4}$ .

$x = - \frac{31 \cdot \frac{4}{4} - \frac{133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.4

Combine $31$ and $\frac{4}{4}$ .

$x = - \frac{\frac{31 \cdot 4}{4} - \frac{133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.5

Combine the numerators over the common denominator.

$x = - \frac{\frac{31 \cdot 4 - 133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.6

Simplify the numerator.

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Step 3.6.2.1.1.6.1

Multiply $31$ by $4$ .

$x = - \frac{\frac{124 - 133}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.6.2

Subtract $133$ from $124$ .

$x = - \frac{\frac{- 9}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{\frac{- 9}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.1.7

Move the negative in front of the fraction.

$x = - \frac{- \frac{9}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{- \frac{9}{4}}{3}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.2

Multiply the numerator by the reciprocal of the denominator.

$x = - (- \frac{9}{4} \cdot \frac{1}{3})$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.3

Cancel the common factor of $3$ .

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Step 3.6.2.1.3.1

Move the leading negative in $- \frac{9}{4}$ into the numerator.

$x = - (\frac{- 9}{4} \cdot \frac{1}{3})$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.3.2

Factor $3$ out of $- 9$ .

$x = - (\frac{3 (- 3)}{4} \cdot \frac{1}{3})$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.3.3

Cancel the common factor.

$x = - (\frac{3 \cdot - 3}{4} \cdot \frac{1}{3})$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.3.4

Rewrite the expression.

$x = - \frac{- 3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = - \frac{- 3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.4

Move the negative in front of the fraction.

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.5

Multiply $- - \frac{3}{4}$ .

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Step 3.6.2.1.5.1

Multiply $- 1$ by $- 1$ .

$x = 1 (\frac{3}{4})$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.2.1.5.2

Multiply $\frac{3}{4}$ by $1$ .

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{20 z}{3}$

Step 3.6.3

Replace all occurrences of $z$ in $y = \frac{67}{6} - \frac{20 z}{3}$ with $\frac{7}{4}$ .

$y = \frac{67}{6} - \frac{20 (\frac{7}{4})}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4

Simplify the right side.

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Step 3.6.4.1

Simplify $\frac{67}{6} - \frac{20 (\frac{7}{4})}{3}$ .

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Step 3.6.4.1.1

Simplify each term.

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Step 3.6.4.1.1.1

Combine $20$ and $\frac{7}{4}$ .

$y = \frac{67}{6} - \frac{\frac{20 \cdot 7}{4}}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.1.2

Multiply $20$ by $7$ .

$y = \frac{67}{6} - \frac{\frac{140}{4}}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.1.3

Divide $140$ by $4$ .

$y = \frac{67}{6} - \frac{35}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{35}{3}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.2

To write $- \frac{35}{3}$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$y = \frac{67}{6} - \frac{35}{3} \cdot \frac{2}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.3

Write each expression with a common denominator of $6$ , by multiplying each by an appropriate factor of $1$ .

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Step 3.6.4.1.3.1

Multiply $\frac{35}{3}$ by $\frac{2}{2}$ .

$y = \frac{67}{6} - \frac{35 \cdot 2}{3 \cdot 2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.3.2

Multiply $3$ by $2$ .

$y = \frac{67}{6} - \frac{35 \cdot 2}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{67}{6} - \frac{35 \cdot 2}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.4

Combine the numerators over the common denominator.

$y = \frac{67 - 35 \cdot 2}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.5

Simplify the numerator.

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Step 3.6.4.1.5.1

Multiply $- 35$ by $2$ .

$y = \frac{67 - 70}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.5.2

Subtract $70$ from $67$ .

$y = \frac{- 3}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{- 3}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.6

Cancel the common factor of $- 3$ and $6$ .

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Step 3.6.4.1.6.1

Factor $3$ out of $- 3$ .

$y = \frac{3 (- 1)}{6}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.6.2

Cancel the common factors.

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Step 3.6.4.1.6.2.1

Factor $3$ out of $6$ .

$y = \frac{3 \cdot - 1}{3 \cdot 2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.6.2.2

Cancel the common factor.

$y = \frac{3 \cdot - 1}{3 \cdot 2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.6.2.3

Rewrite the expression.

$y = \frac{- 1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{- 1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = \frac{- 1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.6.4.1.7

Move the negative in front of the fraction.

$y = - \frac{1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = - \frac{1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = - \frac{1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

$y = - \frac{1}{2}$

$x = \frac{3}{4}$

$z = \frac{7}{4}$

Step 3.7

List all of the solutions.

$y = - \frac{1}{2}, x = \frac{3}{4}, z = \frac{7}{4}$