Объяснение:
(x-y)²+2x(x-y) =(x-y) (x-y+2x)=(x-y) (3х-y)
(x-y)³+(x-y) =(x-y)(x²-2хy+у²+1)
(a+b)³-(a+b)²=(a+b)²(a+b-1)
