8m2-72n2
Factor 8 out of 8m2.
8(m2)-72n2
Factor 8 out of -72n2.
8(m2)+8(-9n2)
Factor 8 out of 8(m2)+8(-9n2).
8(m2-9n2)
8(m2-9n2)
Rewrite 9n2 as (3n)2.
8(m2-(3n)2)
Since both terms are perfect squares, factor using the difference of squares formula, a2-b2=(a+b)(a-b) where a=m and b=3n.
8((m+3n)(m-(3n)))
Multiply 3 by -1.
8((m+3n)(m-3n))
Remove unnecessary parentheses.
8(m+3n)(m-3n)
8(m+3n)(m-3n)
Factor 8m^2-72n^2