# How do you solve 3x − 18 = 21?

Jun 17, 2016

$x = 13$

#### Explanation:

Re=arrange the equation so that all the x terms are on one side and all the numbers are on the other.

$3 x - 18 \textcolor{red}{+ 18} = 21 \textcolor{red}{+ 18}$
$3 x = 39 \text{ divide by 3}$
$x = 13$