1.3.6 Difference of Squares

Everybody should know that $x^2 - y^2 = (x - y)(x + y)$. You can easily apply this trick when asked to find the difference between squares of numbers. For example:

$$54^2 - 55^2 = (54 - 55)(54 + 55) = -109$$

This is a pretty basic trick and is easily recognizable on the test.

Problem Set 1.3.6

Here are some more practice to give you a better feel of the problems: