Example 31

$\;\;\;(3b + 2a^{6})^2$

$=(A + B)^2 \text{, where } A = 3b \text{ and } B = 2a^{6} $

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

$=(3b)^2 + 2(3b)(2a^{6}) + (2a^{6})^2 $

$=9b^{2} + 12a^{6}b +4a^{12} $