The expression is .

To find the LCD and factor each denominator.

Apply difference of the squares form: ).

First denominator : .

Second denominator : .

Then LCD is .

Since the denominators .

                      (Denominators are same and add numerators)

Distribute terms using distributive property: .

                           (Product of two different signs is negative)

Apply commutative property of addition in numerator: a + b = b + a.

                           (Cancel common terms: )

                                   (Apply additive inverse property: )

                                   (Subtract: )

The difference of .