Example 26

$\;\;\;(2y^{7} + x^{3})^2$

$=(A + B)^2 \text{, where } A = 2y^{7} \text{ and } B = x^{3} $

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

$=(2y^{7})^2 + 2(2y^{7})(x^{3}) + (x^{3})^2 $

$=4y^{14} + 4x^{3}y^{7} +x^{6} $