Example 70

$\;\;\;(1 - x^{4}y^{3})^2$

$=(A - B)^2 \text{, where } A = 1 \text{ and } B = x^{4}y^{3} $

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

$=(1)^2 - 2(1)(x^{4}y^{3}) + (x^{4}y^{3})^2 $

$=1 - 2x^{4}y^{3} +x^{8}y^{6} $