Determine the factors of 5x^2 + 6x - 8.

a. (5x - 1) (x + 8)

b. (5x - 8) (x + 1)

c. (5x - 4) (x + 2)

d. (5x - 2) (x + 4)

Use ac method

for ax^2+bx+c

multiply a and c

find what 2 numbers mutiply to get ac and add to get b

split b into those 2 numbers

group

factor

factor

5x^2+6x-8

ac=5 times - 8=-40

what 2 numbers multily to get - 40 and add to get 6?

-4 and 10

5x^2+10x-4x-8

group

(5x^2+10x) + (-4x-8)

factor

5x (x+2) - 4 (x+2)

factor

(5x-4) (x+2)

C is answer