a)

This expression is a classic example of the difference of squares! It can be factored using the formula . Here, you can rewrite as and as . So, the factored form would be . Voila!

Factoring like this not only simplifies expressions but also helps in solving equations efficiently. When you set , for instance, you can find the values of quickly by solving and . Just remember to double-check your signs; misplacing a minus can lead to a head-scratching situation!