Question 123676
What equation???
What you have here is an expression, and expressions can't be "solved" but they can be simplified, or, given enough data, they can be evaluated.

Factor the trinomial:
{{{s^2-15s+50}}}
The factors will look like:
{{{(s+m)*(s+n)}}} where: {{{m*n = 50}}} and {{{m+n = -15}}}
It's not too hard to see that if {{{m = -5}}} and {{{n = -10}}}, then
{{{m*n = (-5)(-10)}}} ={{{50}}} and {{{m+n = -5+(-10)}}}={{{-15}}}, so, the factors of the trinomial are:
{{{s^2-15s+50 = (s-5)(s-10)}}}