Thomas E. answered 03/07/19
Tom E., a Patient and Knowledgeable Mathematics Tutor for You
If you graph out your vertex and root, you will see that this is a parabola pointed downward. All parabolas are asymmetric about the vertical line which runs through the vertex (in this case x=-3). Since one root is 2 to the left of the line (at -5), the other root must be 2 to the right or x=-1.
Ahmed S.
Thanks for your help!03/07/19