упрастите выражение
x(x-1)(x-1)-(x-2)(x^2+2x+4)=

x*(x-1)*(x-1)-(x-2)*(x²+2x+4)=x*(x-1)²-(x³-2³)=x*(x²-2x+1)-x³+8=

=x³-2x²+x-x³+8=-2x²+x+8.