Answer
x=-8 or -1
Work Step by Step
Rewrite the equation in standard form.
x$^2$+9x=-8
x$^2$+9x+8=0
Factor the trinomial.
(x+8)(x+1)=0
Set each variable factor as equal to zero and then isolate the variable to find the solutions.
x+8=0 or x+1=0
x=-8 or x=-1
Enter the original equation into your graphing utility to observe that the graph crosses the x-axis at -8 and -1.