How do you factor the expression x^3y^3 + z^3?

1 Answer
Feb 7, 2016

Answer is: (xy + z)(x^2 y^2 - xyz + z^2).

You can check by multiplying it out.

Explanation:

Notice that each term is a perfect cube: x^3 y^3 = (xy)^3.

So we have a sum of cubes, and the factoring formula is:

a^3 + b^3 = (a+b)(a^2-ab+b^2)

So we use a = xy and b = z to get:

x^3 y^3 + z^3 = (xy)^3 + z^3

= ((xy) +z)((xy)^2-(xy)z+z^2)

=(xy + z)(x^2 y^2 - xyz + z^2).

check by multiplying it out to make sure!

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