Answer:

on simplify:
x+6 = x²
x+6-x²=0
-x²+x+6=0
we change the signs
x²-x-6=0
we write -x as a difference: x²+2x-3x-6=0
we factorize:
x(x+2)-3(x+2)=0
(x+2)(x-3)=0
we solve:
x+2=0 x=-2
x-3=0 x=3
we check:
we replace x by -2:


x-2 equality is false
solution: x=3