Evaluate: x(x + 1)(x - 1)

I think I did this right.

x(x) + x(1) + x(x) + x(-1)

x^2 + 1x + x^2 + -1x

x^2 + 1x^3 + -1x

x^2 - 1x^4 <-- is this right?

Results 1 to 3 of 3

- Jul 6th 2005, 07:11 PM #1

- Joined
- Jun 2005
- Posts
- 58

- Jul 6th 2005, 07:23 PM #2
## FOIL method

x(x + 1)(x - 1)

is the same as

x[(x + 1)(x - 1)], so lets do what is inside the brackets first.

Using FOIL method (FOIL is First Outer Inner Last, ask me if you need clarification)

x[x^2 - x + x - 1]

- x + x cancels, now distribute the x

**x^3 - x**<---ANSWER

- Jul 6th 2005, 07:31 PM #3

- Joined
- Jun 2005
- Posts
- 58