Question 302687
You mean factor the expression?
It's the difference of two squares.
{{{Z^2-W^2=(Z+W)(Z-W)}}}
where
{{{Z=5m}}}, {{{Z^2=25m^2}}}
{{{W=4n}}}, {{{W^2=16n^2}}}
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{{{25m^2-16n^2=(5m+4n)(5m-4n)}}}