Question

Simple Question:

Simplify: x^3+8

I know the answer, so please just show steps so I can learn.. I forgot how to do this :/

Answer 1

That looks like it in in simplest form to me.. unless it want's you to expand the x's?

Answer 2

Yeah, I need it to look like (x+2) times something

Answer 3

is it equal to something? did you write it incorrectly?

Answer 4

Oh umm, I'm solving for a limit, limx->-2 (x+2)/(x^3+8)

Answer 5

You need to complete the cube, using a formula that I forget

Answer 6

So but I don't really understand how to get from x^3+8 to (x+2)(x^2-2x+4)

Answer 7

(x+a)^3 = x^3 +3x^2 a + 3xa^2+a^3

Answer 8

A formula:
\(a^3 + b^3 = (a + b)(a^2 - ab + b^2) \)

Answer 9

his second number isn't a cube though, so that one won't help.

Answer 10

x^3 + 8
8 = 2^3
?

Answer 11

@AccessDenied It doesn't work that that don't forget that we are dealing with a polynominal

Answer 12

how about just looking at the graph

Answer 13

factor (x^3+8) out :D

Answer 14

Ohhh, thanks everyone I get it now. I used AccessDenied's formula :D

Answer 15

http://www.wolframalpha.com/input/?i=limit+as+x+approaches+-2++++%28x%2B2%29%2F%28x%5E3%2B8%29

Answer 16

oh right, 8=2^3.

Answer 17

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


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

a^3 + b^3