Question

Factorise 8x 3 -- (2x -- y) 3 urgent please.

Answer 1

8x^3-(2x-y)^3 = (2x)^3-(2x-y)^3 Apply formula a^3-b^3= (a-b)(a^2-ab+b^2) Put a= 2x,b= 2x-y = (2x-2x+y){(2x)^2-2x*(2x-y)+(2x-y)^2} = y{(4x^2-4x^2+2xy+4x^2-4xy+y^2)} = y (4x^2-2xy+y^2)