Answer:
We can factor a difference of fourth powers (and higher powers) by treating each term as the square of another base, using the power to a power rule. For example, to factor x4 - y4, we treat x4 as (x2)2 and y4 as (y2)2. Thus, x4 - y4 = (x2)2 - (y2)2 = (x2 + y2)(x2 - y2) = (x2 + y2)(x + y)(x - y).
