How do you factor the expression x^2 + 3x + 2?

Mar 30, 2018

${x}^{2} + 3 x + 2 = \left(x + 1\right) \left(x + 2\right)$

Explanation:

Note that in general:

$\left(x + a\right) \left(x + b\right) = {x}^{2} + \left(a + b\right) x + a b$

So can we think of two numbers $a , b$ such that $a + b = 3$ and $a b = 2$ ? How about $1$ and $2$ ?

So:

${x}^{2} + 3 x + 2 = \left(x + 1\right) \left(x + 2\right)$