Factor completely.

5x^2 + 10x - 40

5 (x - 2) (x + 4)

Step-by-step explanation:

5x^2 + 10x - 40

Factor out a 5

5 (x^2 + 2x-8)

We can then factor inside the parentheses

What two numbers multiply to - 8 and add to 2

-2*4 = - 8

-2+4 = 8

5 (x - 2) (x + 4)

5 (x + 4) (x - 2)

Step-by-step explanation:

Start by factoring 5 out of all three terms. We then have

5 (x^2 + 2x - 8), or

5 (x^2 + 2x - 8), which is in proper quadratic form.

Note that (4) (-2) = 8 and that 4 - 2 = 2, which match the 3rd and 2nd coefficients of x^2 + 2x - 8.

Thus, in completely factored form, we have 5 (x + 4) (x - 2)