Answer
$(5z+4)^{2}$
Work Step by Step
Given the polynomial
$(5z)^{2}$ + 40z + $(4)^{2}$
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= 5z and b=4
$(5z)^{2}$ + 2(5z)(4) + $(4)^{2}$ = $(5z+4)^{2}$
