It's simple, you first do -b/2a, (This is how the equation is supposed to go: ax^2+bx+c) Therefore, to this answer, it is -1. Now this answer will be you x point, and you use that to find the vertex by putting -1 as b. You have two choices that are correct, so eliminate those who's x isn't -1. Finally, put -1 as b, which would end up as -1^2+2(-1)-35, and when you simplify it, you end up with -36, making D the answer
