Question

Which is a factor of 8x2 – 12x – 8 ?
a.) x + 1
b.) x – 4
c.) 2x – 2
d.) 2x + 1

Answer 1

use the factor theorem
eg if x+1 is a factor then f(-1) = 0
if 2x +1 is a factor then f(-1/2) = 0

try x+1;

f(-1) = 8(-1)^2 - 12(-1) - 8 = 8+12 -8 = 12 - so x+1 is not a factor

Answer 2

or you can try factorising
8x^2 - 12x - 8
=4(2x^2 - 3x - 2)
= 4(2x + 1)(x - 2)

- thats it

Answer 3

I suggest you to do factorization
8x^2 – 12x – 8
= 4 (2x^2 -3x -2)
= 4 ( 2x +1) (x-2)

Answer 4

Thank you.

Answer 5

Got it...
8x2-12x-8=4(2x2-3x-2)
=4(2x2+x-4x-2)
=4(x(2x+1)-2(2x+1))
=4(x-2)(2x+1)