Algebra Examples

x^{2} - 3 x - 40

$x^{2} - 3 x - 40$

Step 1

Consider the form

x^{2} + b x + c

$x^{2} + b x + c$ . Find a pair of integers whose product is

c

$c$ and whose sum is

b

$b$ . In this case, whose product is

- 40

$- 40$ and whose sum is

- 3

$- 3$ .

- 8, 5

$- 8, 5$

Step 2

Write the factored form using these integers.

(x - 8) (x + 5)

$(x - 8) (x + 5)$