Which quadratic evaluation is to (x-4) ^2 - (x-4) - 6 = 0

We need the chocies but I can factor and solve

subsitute

u=x-4

u^2-u-6=0

what 2 numbers multily to get - 6 and add to get - 1

-3 and 2

(u-3) (u+2) = 0

set to zero

u-3=0

u=3

u+2=0

u=-2

but u=x-4

3=x-4

7=x

-2=x-4

2=x

x=2,7