Answer
$(6m^{2}+7)^{2}$
Work Step by Step
Given the polynomial
$(6m^{2})^{2}$ + 84$m^{2}$ + $(7)^{2}$
We see that the polynomial has the first and last term squared and the middle term is +2 times the first and last term. Thus it follows the rule of
$a^{2}$ + 2ab + $b^{2}$ = $(a+b)^{2}$
In this polynomial a= $6m^{2}$ and b=7
$6m^{2}$ + 2($6m^{2}$)(7) + $(7)^{2}$ = $(6m^{2}+7)^{2}$