Finite Math Examples

$7 x + 3 y + 5 z = 16$ , $3 x + y + 2 z = 20$

Step 1

Solve the equation for $x$ .

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Step 1.1

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

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Step 1.1.1

Subtract $3 y$ from both sides of the equation.

$7 x + 5 z = 16 - 3 y$

$3 x + y + 2 z = 20$

Step 1.1.2

Subtract $5 z$ from both sides of the equation.

$7 x = 16 - 3 y - 5 z$

$3 x + y + 2 z = 20$

$7 x = 16 - 3 y - 5 z$

$3 x + y + 2 z = 20$

Step 1.2

Divide each term in $7 x = 16 - 3 y - 5 z$ by $7$ and simplify.

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Step 1.2.1

Divide each term in $7 x = 16 - 3 y - 5 z$ by $7$ .

$\frac{7 x}{7} = \frac{16}{7} + \frac{- 3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

Step 1.2.2

Simplify the left side.

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Step 1.2.2.1

Cancel the common factor of $7$ .

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Step 1.2.2.1.1

Cancel the common factor.

$\frac{7 x}{7} = \frac{16}{7} + \frac{- 3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

Step 1.2.2.1.2

Divide $x$ by $1$ .

$x = \frac{16}{7} + \frac{- 3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} + \frac{- 3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} + \frac{- 3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

Step 1.2.3

Simplify the right side.

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Step 1.2.3.1

Simplify each term.

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Step 1.2.3.1.1

Move the negative in front of the fraction.

$x = \frac{16}{7} - \frac{3 y}{7} + \frac{- 5 z}{7}$

$3 x + y + 2 z = 20$

Step 1.2.3.1.2

Move the negative in front of the fraction.

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$3 x + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$3 x + y + 2 z = 20$

Step 2

Solve the equation for $z$ .

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Step 2.1

Simplify $3 (\frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}) + y + 2 z$ .

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Step 2.1.1

Simplify each term.

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Step 2.1.1.1

Apply the distributive property.

$3 (\frac{16}{7}) + 3 (- \frac{3 y}{7}) + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2

Simplify.

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Step 2.1.1.2.1

Multiply $3 (\frac{16}{7})$ .

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Step 2.1.1.2.1.1

Combine $3$ and $\frac{16}{7}$ .

$\frac{3 \cdot 16}{7} + 3 (- \frac{3 y}{7}) + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.1.2

Multiply $3$ by $16$ .

$\frac{48}{7} + 3 (- \frac{3 y}{7}) + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} + 3 (- \frac{3 y}{7}) + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.2

Multiply $3 (- \frac{3 y}{7})$ .

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Step 2.1.1.2.2.1

Multiply $- 1$ by $3$ .

$\frac{48}{7} - 3 \frac{3 y}{7} + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.2.2

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

$\frac{48}{7} + \frac{- 3 (3 y)}{7} + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.2.3

Multiply $3$ by $- 3$ .

$\frac{48}{7} + \frac{- 9 y}{7} + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} + \frac{- 9 y}{7} + 3 (- \frac{5 z}{7}) + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.3

Multiply $3 (- \frac{5 z}{7})$ .

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Step 2.1.1.2.3.1

Multiply $- 1$ by $3$ .

$\frac{48}{7} + \frac{- 9 y}{7} - 3 \frac{5 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.3.2

Combine $- 3$ and $\frac{5 z}{7}$ .

$\frac{48}{7} + \frac{- 9 y}{7} + \frac{- 3 (5 z)}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.2.3.3

Multiply $5$ by $- 3$ .

$\frac{48}{7} + \frac{- 9 y}{7} + \frac{- 15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} + \frac{- 9 y}{7} + \frac{- 15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} + \frac{- 9 y}{7} + \frac{- 15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.3

Simplify each term.

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Step 2.1.1.3.1

Move the negative in front of the fraction.

$\frac{48}{7} - \frac{9 y}{7} + \frac{- 15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.1.3.2

Move the negative in front of the fraction.

$\frac{48}{7} - \frac{9 y}{7} - \frac{15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} - \frac{9 y}{7} - \frac{15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{48}{7} - \frac{9 y}{7} - \frac{15 z}{7} + y + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.2

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

$\frac{48}{7} - \frac{15 z}{7} - \frac{9 y}{7} + y \cdot \frac{7}{7} + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.3

Simplify terms.

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Step 2.1.3.1

Combine $y$ and $\frac{7}{7}$ .

$\frac{48}{7} - \frac{15 z}{7} - \frac{9 y}{7} + \frac{y \cdot 7}{7} + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.3.2

Combine the numerators over the common denominator.

$\frac{48}{7} - \frac{15 z}{7} + \frac{- 9 y + y \cdot 7}{7} + 2 z = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.3.3

Combine the numerators over the common denominator.

$2 z + \frac{48 - 15 z - 9 y + y \cdot 7}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$2 z + \frac{48 - 15 z - 9 y + y \cdot 7}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.4

Move $7$ to the left of $y$ .

$2 z + \frac{48 - 15 z - 9 y + 7 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.5

Add $- 9 y$ and $7 y$ .

$2 z + \frac{48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.6

To write $2 z$ as a fraction with a common denominator, multiply by $\frac{7}{7}$ .

$2 z \cdot \frac{7}{7} + \frac{48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.7

Simplify terms.

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Step 2.1.7.1

Combine $2 z$ and $\frac{7}{7}$ .

$\frac{2 z \cdot 7}{7} + \frac{48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.7.2

Combine the numerators over the common denominator.

$\frac{2 z \cdot 7 + 48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{2 z \cdot 7 + 48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.8

Simplify the numerator.

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Step 2.1.8.1

Multiply $7$ by $2$ .

$\frac{14 z + 48 - 15 z - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.8.2

Subtract $15 z$ from $14 z$ .

$\frac{- z + 48 - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$\frac{- z + 48 - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9

Simplify with factoring out.

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Step 2.1.9.1

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

$\frac{- (z) + 48 - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.2

Rewrite $48$ as $- 1 (- 48)$ .

$\frac{- (z) - 1 \cdot - 48 - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.3

Factor $- 1$ out of $- (z) - 1 (- 48)$ .

$\frac{- (z - 48) - 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.4

Factor $- 1$ out of $- 2 y$ .

$\frac{- (z - 48) - (2 y)}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.5

Factor $- 1$ out of $- (z - 48) - (2 y)$ .

$\frac{- (z - 48 + 2 y)}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.6

Simplify the expression.

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Step 2.1.9.6.1

Rewrite $- (z - 48 + 2 y)$ as $- 1 (z - 48 + 2 y)$ .

$\frac{- 1 (z - 48 + 2 y)}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.1.9.6.2

Move the negative in front of the fraction.

$- \frac{z - 48 + 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$- \frac{z - 48 + 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$- \frac{z - 48 + 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$- \frac{z - 48 + 2 y}{7} = 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.2

Multiply both sides of the equation by $- 7$ .

$- 7 (- \frac{z - 48 + 2 y}{7}) = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3

Simplify both sides of the equation.

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Step 2.3.1

Simplify the left side.

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Step 2.3.1.1

Simplify $- 7 (- \frac{z - 48 + 2 y}{7})$ .

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Step 2.3.1.1.1

Cancel the common factor of $7$ .

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Step 2.3.1.1.1.1

Move the leading negative in $- \frac{z - 48 + 2 y}{7}$ into the numerator.

$- 7 \frac{- (z - 48 + 2 y)}{7} = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.1.1.1.2

Factor $7$ out of $- 7$ .

$7 (- 1) (\frac{- (z - 48 + 2 y)}{7}) = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.1.1.1.3

Cancel the common factor.

$7 \cdot (- 1 \frac{- (z - 48 + 2 y)}{7}) = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.1.1.1.4

Rewrite the expression.

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.1.1.2

Multiply.

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Step 2.3.1.1.2.1

Multiply $- 1$ by $- 1$ .

$1 (z - 48 + 2 y) = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.1.1.2.2

Multiply $z - 48 + 2 y$ by $1$ .

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 7 \cdot 20$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.3.2

Simplify the right side.

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Step 2.3.2.1

Multiply $- 7$ by $20$ .

$z - 48 + 2 y = - 140$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 140$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z - 48 + 2 y = - 140$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.4

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

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Step 2.4.1

Add $48$ to both sides of the equation.

$z + 2 y = - 140 + 48$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.4.2

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

$z = - 140 + 48 - 2 y$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 2.4.3

Add $- 140$ and $48$ .

$z = - 92 - 2 y$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z = - 92 - 2 y$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

$z = - 92 - 2 y$

$x = \frac{16}{7} - \frac{3 y}{7} - \frac{5 z}{7}$

Step 3

Simplify the right side.

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Step 3.1

Simplify $\frac{16}{7} - \frac{3 y}{7} - \frac{5 (- 92 - 2 y)}{7}$ .

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Step 3.1.1

Combine the numerators over the common denominator.

$x = \frac{16 - 3 y - 5 (- 92 - 2 y)}{7}$

$z = - 92 - 2 y$

Step 3.1.2

Simplify each term.

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Step 3.1.2.1

Apply the distributive property.

$x = \frac{16 - 3 y - 5 \cdot - 92 - 5 (- 2 y)}{7}$

$z = - 92 - 2 y$

Step 3.1.2.2

Multiply $- 5$ by $- 92$ .

$x = \frac{16 - 3 y + 460 - 5 (- 2 y)}{7}$

$z = - 92 - 2 y$

Step 3.1.2.3

Multiply $- 2$ by $- 5$ .

$x = \frac{16 - 3 y + 460 + 10 y}{7}$

$z = - 92 - 2 y$

$x = \frac{16 - 3 y + 460 + 10 y}{7}$

$z = - 92 - 2 y$

Step 3.1.3

Simplify terms.

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Step 3.1.3.1

Add $16$ and $460$ .

$x = \frac{- 3 y + 476 + 10 y}{7}$

$z = - 92 - 2 y$

Step 3.1.3.2

Add $- 3 y$ and $10 y$ .

$x = \frac{7 y + 476}{7}$

$z = - 92 - 2 y$

Step 3.1.3.3

Cancel the common factor of $7 y + 476$ and $7$ .

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Step 3.1.3.3.1

Factor $7$ out of $7 y$ .

$x = \frac{7 (y) + 476}{7}$

$z = - 92 - 2 y$

Step 3.1.3.3.2

Factor $7$ out of $476$ .

$x = \frac{7 (y) + 7 \cdot 68}{7}$

$z = - 92 - 2 y$

Step 3.1.3.3.3

Factor $7$ out of $7 (y) + 7 (68)$ .

$x = \frac{7 (y + 68)}{7}$

$z = - 92 - 2 y$

Step 3.1.3.3.4

Cancel the common factors.

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Step 3.1.3.3.4.1

Factor $7$ out of $7$ .

$x = \frac{7 (y + 68)}{7 (1)}$

$z = - 92 - 2 y$

Step 3.1.3.3.4.2

Cancel the common factor.

$x = \frac{7 (y + 68)}{7 \cdot 1}$

$z = - 92 - 2 y$

Step 3.1.3.3.4.3

Rewrite the expression.

$x = \frac{y + 68}{1}$

$z = - 92 - 2 y$

Step 3.1.3.3.4.4

Divide $y + 68$ by $1$ .

$x = y + 68$

$z = - 92 - 2 y$

$x = y + 68$

$z = - 92 - 2 y$

$x = y + 68$

$z = - 92 - 2 y$

$x = y + 68$

$z = - 92 - 2 y$

$x = y + 68$

$z = - 92 - 2 y$

$x = y + 68$

$z = - 92 - 2 y$

Step 4

Simplify the right side.

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Step 4.1

Reorder $- 92$ and $- 2 y$ .

$z = - 2 y - 92$

$x = y + 68$

$z = - 2 y - 92$

$x = y + 68$