Question 558372
-1813 sounds like the answer to a very different problem.
{{{(x+18)(x-13)(x+16)>0}}} is an inequality.
Solutions to inequalities usually involve a set of infinite values such as x>something or other. I cannot think of any inequality whose answer is a single number.
The solution to {{{(x+18)(x-13)(x+16)>0}}} is
{{{x>13}}} or {{{-18<x<-16}}}
That includes 14, 15, 16, -17, and infinitely more values for x.
You get to the solution by figuring out where each factor is positive and where each factor is negative.