Answer
$(6s-5)^{2}$
Work Step by Step
$36s^{2}-60s+25=$
...write first and last terms as squares.
$=(6s)^{2}-60s+5^{2}$
...does middle term equal $2ab$?
$60s=2\cdot(6s)\cdot(5)$
$=(6s)^{2}-2\cdot(6s)\cdot(5)+5^{2}$
...write as the square of a binomial.
$=(6s-5)^{2}$
