# How do you factor by grouping 9x^2 + 3xy + 3x + y?

May 23, 2015

$9 {x}^{2} + 3 x y + 3 x + y$

$= \left(9 {x}^{2} + 3 x y\right) + \left(3 x + y\right)$

$= 3 x \left(3 x + y\right) + \left(3 x + y\right)$

$= \left(3 x + 1\right) \left(3 x + y\right)$