What is the product of this given equation ?

Question

(a^2 - f^2)(a^2 + f^2)=?

Answer 1

The rule for factoring the difference of two squares (say A²-B²) is as follows:  A²-B²=(A+B)(A-B).

Applying this rule (in reverse) to the above, we get:  (a²-f²)(a²+f²)=(a²)²-(f²)² = a⁴-f⁴

 

Another way to do this problem, is to completely multiply out the factors provided and combine like terms, as follows:

(a²-f²)(a²+f²) = a²a²+a²f²-a²f²-f⁴ = a⁴-f⁴