Question

x³+x²-x³-x² - 6x-6=0.

Answer 1

$x^{3}+x^{2} -x^{3}-x^{2}-6x-6=0\\-6x-6=0|*(-1)\\6x+6=0\\6(x+1)=0 |:6\\x+1 =0\\x=-1$