Linear Algebra Examples

$9 x - 5 - 2 x = 16$

Step 1

Subtract $2 x$ from $9 x$ .

$7 x - 5 = 16$

Step 2

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

Tap for more steps...

Step 2.1

Add $5$ to both sides of the equation.

$7 x = 16 + 5$

Step 2.2

Add $16$ and $5$ .

$7 x = 21$

Step 3

Divide each term in $7 x = 21$ by $7$ and simplify.

Tap for more steps...

Step 3.1

Divide each term in $7 x = 21$ by $7$ .

$\frac{7 x}{7} = \frac{21}{7}$

Step 3.2

Simplify the left side.

Tap for more steps...

Step 3.2.1

Cancel the common factor of $7$ .

Tap for more steps...

Step 3.2.1.1

Cancel the common factor.

$\frac{7 x}{7} = \frac{21}{7}$

Step 3.2.1.2

Divide $x$ by $1$ .

$x = \frac{21}{7}$

Step 3.3

Simplify the right side.

Tap for more steps...

Step 3.3.1

Divide $21$ by $7$ .

$x = 3$

Step 4

The domain is the set of all valid $x$ values.

${x | x = 3}$

Step 5