Algebra Examples

Factor $x^{2} - 2 x - 15$

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 $- 15$ and whose sum is $- 2$ .

$- 5, 3$

Step 2

Write the factored form using these integers.

$(x - 5) (x + 3)$