# How do you simplify #(x + 1)(x - 1)#?

##### 1 Answer

Jun 22, 2018

#### Answer:

#### Explanation:

Before we attempt to multiply this out, what do you notice about the binomial given?

If fits the **difference of squares pattern**

Essentially, our

Now, every product of binomials won't be in this form, but we can use **FOIL** (Firsts, Outsides, Insides, Lasts), which will work every time. This is the order we multiply in.

- Multiply the first terms:
#x*x=x^2# - Multiply the outside terms:
#x*-1=-x# - Multiply the inside terms:
#1*x=x# - Multiply the last term:
#1*-1=-1#

This is equal to

The middle terms cancel, and we're left with

Remember, FOIL will work every time, but if we see a product of binomials of the form

Hope this helps!