Example 65

$\;\;\;(2x^{5}y^{4} - 1)^2$

$=(A - B)^2 \text{, where } A = 2x^{5}y^{4} \text{ and } B = 1 $

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

$=(2x^{5}y^{4})^2 - 2(2x^{5}y^{4})(1) + (1)^2 $

$=4x^{10}y^{8} - 4x^{5}y^{4} +1 $