How can -x^3 + 27 be factored?

Draggu · Feb 4, 2009

Homework Statement

factor -x^3 + 27

Nothing, I have no idea how to factor it.

Mark44 · Feb 4, 2009

Here are a couple of formulas for you:
a³ + b³ = (a + b)(a² - ab + b²)
a³ - b³ = (a - b)(a² + ab + b²)

Draggu · Feb 4, 2009

Mark44 said:

Here are a couple of formulas for you:
a³ + b³ = (a + b)(a² - ab + b²)
a³ - b³ = (a - b)(a² + ab + b²)

I tried those. My main problem is the -x^3.

Dick · Feb 4, 2009

You've got 3^3-x^3. That fits the second formula Mark44 gave you.

MattRSK · Aug 15, 2009

2 seconds on physics forum and I found what I'm after. Thanks very much.

HallsofIvy · Aug 15, 2009

Sorry we took so long!