Question 1001170
<pre>
{{{3s^3+15s^2+12s=-60}}}

Divide through by 3

{{{s^3+5s^2+4s=-20}}}

{{{s^3+5s^2+4s+20=0}}}

Factor sē out of the first two terms on the left side.
Factor +4 out of the last two terms on the left side.

{{{s^2(s+5)+4(s+5)=0}}}

Factor (s+5) out of both terms on the left side.

{{{(s+5)(s^2+4)=0}}}

{{{s+5=0}}}; {{{s^2+4=0}}}

{{{s=-5}}};  {{{s^2=-4}}}

There are no real number square roots of negative numbers, so
the equation {{{s^2=-4}}} does not have a real number solution,
so the only real number solution is s = -5.

Edwin</pre>