Answer
$(2x-5)^{2}$
Work Step by Step
Given the polynomial
$4x^{2}$ - 20x + 25
We rewrite it so that the first and last terms are squared.
$(2x)^{2}$ - 20x + $(5)^{2}$
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= 2x and b=5
$(2x)^{2}$ - 2(2x)(5) + $(5)^{2}$ = $(2x-5)^{2}$
