Example 77

$\;\;\;(11y^{2} - 4x^{6})^2$

$=(A - B)^2 \text{, where } A = 11y^{2} \text{ and } B = 4x^{6} $

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

$=(11y^{2})^2 - 2(11y^{2})(4x^{6}) + (4x^{6})^2 $

$=121y^{4} - 88x^{6}y^{2} +16x^{12} $