Answer
$(s-5)(s+8)$.
Work Step by Step
The given polynomial is
$=s^2+3s-40$
Standard form is $x^2+bx+c$.
We have $b=3$ and $c=-40$.
$b$ is positive and $c$ is negative.
Factor pair of $-40$, whose sum is $3$:-
$-5,8$
The values of $p$ and $q$ are $-5$ and $8$.
Hence, the factor of the polynomial is $(s+p)(s+q)=(s-5)(s+8)$.
Check:-
$=(s-5)(s+8)$
$=s^2+8s-5s-40$
$=s^2+3s-40$
True.
