# How do you combine (x + 3)(x + 4)?

Jun 6, 2015

You can use FOIL:

First + Outside + Inside + Last

$\left(x + 3\right) \left(x + 4\right) = x \cdot x + x \cdot 4 + 3 \cdot x + 3 \cdot 4$

$= {x}^{2} + 4 x + 3 x + 12$

$= {x}^{2} + \left(4 + 3\right) x + 12$

$= {x}^{2} + 7 x + 12$