Answer
$8(s-4)^{2}$
Work Step by Step
Given the polynomial
$8s^{2}$ - 64s + 128
We see that all three terms have a common factor of 8, so we factor out the 8.
$8(s^{2} - 8s + 16)$
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 + $b^{2}$ = $(a-b)^{2}$
8($(s)^{2}$ - 8s + $4^{2}$)
In this polynomial a= s and b=4
8($(s)^{2}$ - 8s + $4^{2}$) = $8(s-4)^{2}$