Question

(х^2-2х)^2+(х^2-2х)=12

Answer 1

(x²-2x)²+(x²-2x)-12=0
x²-2x=a
a²+a-12=0
D=1²-4*(-12)=1+48=49=7²
a=(-1±7)/2
a1=6/2=3
a2=-8/2=-4

x²-2x=3
x²-2x-3=0
D=4+12=16
x=(2±4)/2
x1=3
x2=-1

x²-2x=-4
x²-2x+4=0
D=2-16=-14<0