Question

How do I solve 12x^2-89x-56 factor by grouping

Answer 1

use ac method

multiply 12 and -56
-672
now find what 2 factors of -672 add to -89
answer is -96 and 7

expand the middle term like that
12x²-96x+7x-56
group
(12x²-96x)+(7x-56)
factor
12x(x-8)+7(x-8)
undistribute the (x-8)
(x-8)(12x+7) is answer