Question #3fdac

1 Answer
Jan 20, 2015

The key is to use powers to express your two terms.

Your first term can be written as 8 = 2^38=23, and your second term can be written as z^6 = (z^2)^3z6=(z2)3, which makes your expression

2^3 + (z^2)^3 = (2 + z^2)(2^2 -2*z^2 + (z^2)^2)23+(z2)3=(2+z2)(222z2+(z2)2)

2^3 + (z^2)^3 = (2 + z^2)(4 - 2z^2 + z^4)23+(z2)3=(2+z2)(42z2+z4)

I've used the fact that

a^3 + b^3 = (a+b)(a^2 - ab + b^2)a3+b3=(a+b)(a2ab+b2)