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