Example 74

$\;\;\;(4k^{8} - 3l^{7})^2$

$=(A - B)^2 \text{, where } A = 4k^{8} \text{ and } B = 3l^{7} $

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

$=(4k^{8})^2 - 2(4k^{8})(3l^{7}) + (3l^{7})^2 $

$=16k^{16} - 24k^{8}l^{7} +9l^{14} $