How do you factor 5x3+40y6?

1 Answer
May 18, 2015

You can use a formula for a sum of cubes:
a3+b3=(a+b)(a2ab+b2)

Notice that 40y6=58y6=523(y2)3=5(2y2)3

Using the above formula for a=x and b=2y2 and factoring out constant 5, we get:
5x3+40y6=5x3+5(2y2)3=5(x+2y2)(x22xy2+4y4))