F (x) = - (x2 + x - 72) what is the axis of symmetry and write it in standard form

F (x) = - (x2+x-72)

y = - (x - 8) (x + 9)

the solutions are x = 8, - 9; so the parabola is upside down (umbrella) crossing the x at 8 and - 9, meaning that - 9 + 8 = - 1/2 = - 0.5 is where the focus is, or x = - 0.5 as the axis of symmetry