Example 104

$\;\;\;(5u^{5} + 4v^{10})(5u^{5} - 4v^{10})$

$=(A + B)( A - B) \text{ , where } A = 5u^{5} \text{ and } B = 4v^{10} $

$=A^2-B^2$

$=(5u^{5})^2 - (4v^{10})^2 $

$=25u^{10} - 16v^{20} $