How do you factor x3+8y3?

1 Answer
Sep 23, 2015

Use the sum of cubes identity a3+b3=(a+b)(a2ab+b2) to find:

x3+8y3=(x+2y)(x22xy+4y2)

Explanation:

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

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

=(x+2y)(x2x2y+(2y)2)

=(x+2y(x22xy+4y2)