x=-5 or -3
Work Step by Step
Factor the trinomial. x$^2$+8x+15=0 (x+5)(x+3)=0 Set each variable factor as equal to zero and then isolate the variable to find the solutions. x+5=0 or x+3=0 x=-5 or x=-3 Enter the original equation into your graphing utility to observe that the graph crosses the x-axis at -5 and -3.