Question

(2x-7)^2-4(2x-7)-12=0, i see there are 2 (2x-7) in this equation. Is there a purpose for that? How do i go about this one, now??? thank you

Answer 1

it might help to replace the (2x-7) with another variable, say z

let z = 2x-7

so that allows us to go from this

2x-7)^2-4(2x-7)-12=0

to this

z^2-4z-12=0

Answer 2

solve z^2-4z-12=0 for z. You'll get 2 solutions. Each solution in terms of z will then be used to find the solutions in terms of x

Answer 3

how do i get 3 z's in a factoring.

Answer 4

to factor z^2-4z-12, you need to think of 2 numbers that

multiply to -12 (last term) AND add to -4 (middle coefficient)

Answer 5

what two numbers do this?

Answer 6

wait nevermind, i got it (u+2)(u-6)=0