Question

The question is -x^2+18x-75.

Answer 1

When you use -b/2a you plug in a and b. in this case it would be -18/-2 which coms out as 9. then you plug 9 into x. -9^2+18(9)-75 which comes out as -12. Your vertex is (9,-12) your Axis of semmetry would be 9.