# How do you solve for x in y=mx+b?

May 2, 2016

$x = \frac{y - b}{m}$ (with the obvious restriction $m \ne 0$)

#### Explanation:

If
$\textcolor{w h i t e}{\text{XXX}} y = m x + b$

subtracting $b$ from both sides
$\textcolor{w h i t e}{\text{XXX}} y - b = m x$

dividing both sides by $m$
$\textcolor{w h i t e}{\text{XXX}} \frac{y - b}{m} = x$

flipping the sides (to make it look more normal)
$\textcolor{w h i t e}{\text{XXX}} x = \frac{y - b}{m}$