# How do you factor 9x - 36?

$9 x - 36 = 9 \cdot \left(x - 4\right)$
Since both $9 x$ and $36$ divide by $9$ you can put $9$ as one factor:
$9 x - 36 = 9 \cdot x - 9 \cdot 4 = 9 \cdot \left(x - 4\right)$