# How do you factor 6ab - 21 + 14a - 9b?

Nov 25, 2015

Change the order of the terms then factor by grouping to find:

$6 a b - 21 + 14 a - 9 b = \left(3 b + 7\right) \left(2 a - 3\right)$

#### Explanation:

$6 a b - 21 + 14 a - 9 b$

$= 6 a b - 9 b + 14 a - 21$

$= \left(6 a b - 9 b\right) + \left(14 a - 21\right)$

$= 3 b \left(2 a - 3\right) + 7 \left(2 a - 3\right)$

$= \left(3 b + 7\right) \left(2 a - 3\right)$