#### Answer

x=-3

#### Work Step by Step

Factor the trinomial.
x$^2$+6x+9=0
(x+3)(x+3)=0
Set each variable factor as equal to zero and then isolate the variable to find the solutions.
x+3=0 or x+3=0
x=-3 or x=-3
Enter the original equation into your graphing utility to observe that the graph crosses the x-axis at -3.