Example 71

$\;\;\;(q^{2} - 4p^{4})^2$

$=(A - B)^2 \text{, where } A = q^{2} \text{ and } B = 4p^{4} $

$=A^2 - 2AB + B^2$

$=(q^{2})^2 - 2(q^{2})(4p^{4}) + (4p^{4})^2 $

$=q^{4} - 8p^{4}q^{2} +16p^{8} $