Question

9 ( x - y )3 - ( x - y )

Answer 1

9(x - y)3-(x - y) = (9x -9y)3 -(x-y) = 27x -27y - (x-y) = 27x + (-27y) - (x - y)  = 27x + (-27y) + (-x) + (-y) = 27x + (-x) +(-27y) + (-y) = 26x + (-27y) + (-y) = 26x + (-28y)

Solucion es igual a 26x + (-28y)