# How do you solve 21 + m = 8 m - 3 ( 3 m - 3 )?

May 4, 2018

By arranging the equation

#### Explanation:

$21 + m = 8 m - 3 \left(3 m - 3\right)$

First get rid of the paranthesis:

$21 + m = 8 m - 9 m + 9$

Now collect terms including m on the lest hand side and numbers on the other:

$m - 8 m + 9 m = 9 - 21$

$2 m = - 12$

$m = - \frac{12}{2} = - 6$

Your answer is $m = - 6$