# How do you factor the expression #x^2 - 169#?

##### 2 Answers

#### Explanation:

This is a difference of two squares so it factors as

**Warning**: Differences of squares only works when there is a minus between the two terms, and doesn't work if it is positive. A sum of squares can't be factored with real numbers

Below are a few exercises to practice yourself. Watch out for the trick question(s) near the end!!:)

- Factor each expression
**completely**

a)

b)

c)

d)

Hopefully this helps. Best of luck in the future!

#### Explanation:

What we have is a difference of squares, which has the form

In our example,

Hope this helps!