Question

Sum and Difference of Cubes
Can someone show me an example?

Answer 1

\[(x + 3)^{3} = (x + 3)( x^{2} - 3 * x + 3^{2}) = (x + 3)(x^{2} - 3x + 9)\]
\[(x - 3)^{3} = (x - 3)( x^{2} + 3 * x + 3^{2}) = (x - 3)(x^{2} + 3x + 9)\]

Basically the only differences are going to be the sign in the first factor: (x + 3) or (x - 3), and the first sign in the second term.
Also note that you can't factor the second factor, even though it almost looks like you can

Answer 2

what i had to use 6 instead of 3? what would I change in what you just did?

Answer 3

Well the 6s go in place of all of the 3s I had. If you look at the middle section of the equal signs, I showed where all the 3's went, so you can replace them with 6s, like this

\[(x + 6)^{3} = (x + 6)( x^{2} - 6 * x + 6^{2}) \]

Which then gives you

\[(x + 6)(x^{2} - 6x + 36)\]

Hope that helps :)

Answer 4

thankyou