Question

(x^2+x)^2-8x^2-8x+12=0

Answer 1

(x²+x)²-8x²-8x+12=0
(x²+x)² -8(x²+x) +12=0,    x²+x=t
t²-8t+12=0
t1=6    x²+x=6  x²+x-6=0    x1=-3  x2=2
t2=2    x²+x=2²  x²+x-2=0    x3=-2  x4=1