Можно представить как квадрат суммы:

[tex](8m+7b)^{2} =64m^{2} +2*8m*7b+49b^{2} =64m^{2} +112mb+49b^{2}[/tex]

Verified answer

[tex]\displaystyle\bf\\64m^{2} +112mb+49b^{2} =(8m)^{2} +2\cdot 8m\cdot 7b+(7b)^{2} =\\\\=(8m+7b)^{2} =(8m+7b)\cdot(8m+7b)[/tex]