Answer
$(x-4)(x-4)$
Work Step by Step
The given expression, $
x^2-8x+16
,$ has $c=
16
$ and $b=
-8
.$
The possible factors of $c$ are $
\{ 1,16 \}
,\{ 2,8 \}
,\{ 4,4 \}
,\{ -1,-16 \}
,\{ -2,-8 \}
,\{ -4,-4 \}
$. Among these factors, the pair whose sum is equal to $b$ is $\{
-4,-4
\}.$ Hence, the factored form is
\begin{array}{l}\require{cancel}
(x-4)(x-4)
.\end{array}