Question

PLEASE, I need help!

(08.03 MC)

What are the factors of 5x2 + 39x − 8? (5 points)

(5x − 4)(x + 2)
(5x − 2)(x + 4)
(5x − 1)(x + 8)
(5x − 8)(x + 1)

Answer 1

Its C

Explanation:

I took the test and got it right

Answer 2

5x^2+39x-8 (this is of the form ax^2+bx+c)

find jk=ac=-40 and j+k=b=39, so j and k are 40 and -1

now replace bx with jx and kx...

5x^2+40x-x-8 now factor first and second pair of terms...

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

(5x-1)(x+8)