Precalculus Examples

$x^{2} - 9 x - 220$

Step 1

Consider the form $x^{2} + b x + c$ . Find a pair of integers whose product is $c$ and whose sum is $b$ . In this case, whose product is $- 220$ and whose sum is $- 9$ .

$- 20, 11$

Step 2

Write the factored form using these integers.

$(x - 20) (x + 11)$