# How do you factor x^2 + 13x + 42?

Jul 23, 2016

$\left(x + 6\right) \left(x + 7\right)$

#### Explanation:

In trying to find the factors, we read from the right to the left.

Find factors of 42 which ADD (+) to give 13.

The + also tell us that both signs will be the SAME, they will both be + (because of +13)

There are several factor pairs of 42:
$1 \times 42 \text{ sum is} 43$
$2 \times 21 \text{ sum is} 23$
$3 \times 14 \text{ sum is} 17$
$6 \times 7 \text{ sum is" 13 rArr " these are the factors we want}$

$\left(x + 6\right) \left(x + 7\right)$