Example 107

$\;\;\;(5 + 6v^{3})(5 - 6v^{3})$

$=(A + B)( A - B) \text{ , where } A = 5 \text{ and } B = 6v^{3} $

$=A^2-B^2$

$=(5)^2 - (6v^{3})^2 $

$=25 - 36v^{6} $