Example 17

$\;\;\;(5p^{8} + 6q^{9})^2$

$=(A + B)^2 \text{, where } A = 5p^{8} \text{ and } B = 6q^{9} $

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

$=(5p^{8})^2 + 2(5p^{8})(6q^{9}) + (6q^{9})^2 $

$=25p^{16} + 60p^{8}q^{9} +36q^{18} $