(4-x)*(4-x)*(1-x)=? (2-x)*(-7-x)*(-4-x)=? и почему

Question

(4-x)*(4-x)*(1-x)=?

(2-x)*(-7-x)*(-4-x)=?

и почему

Answer 1

(4-x)*(4-x)*(1-x)=(4-х)^2 *(1-x)=(16-8x+x)*(1-x)=16-16x-8x+8x^2+x-x^2=7x^2-23x+16
(2-x)*(-7-x)*(-4-x)= (-14-2x+7x+x^2)*(-4-x)=(x^2+5x-14)(-4-x)=-4x^2-x^3-20x-5x^2+56+14x=-x^3-9x^2-6x+56