How do you factor x^3+8y^3x3+8y3?

1 Answer
Sep 23, 2015

Use the sum of cubes identity a^3+b^3 = (a+b)(a^2-ab+b^2)a3+b3=(a+b)(a2ab+b2) to find:

x^3+8y^3 = (x+2y)(x^2-2xy+4y^2)x3+8y3=(x+2y)(x22xy+4y2)

Explanation:

Use the sum of cubes identity with a = xa=x and b = 2yb=2y:

x^3+8y^3 = x^3 + (2y)^3x3+8y3=x3+(2y)3

= (x+2y)(x^2-x*2y+(2y)^2)=(x+2y)(x2x2y+(2y)2)

= (x+2y(x^2-2xy+4y^2)=(x+2y(x22xy+4y2)