The axis of symmetry of the parabola y = - X & # 178; - 6x is a straight line? The maximum value of the function is?

The axis of symmetry of the parabola y = - X & # 178; - 6x is a straight line? The maximum value of the function is?

The axis of symmetry of parabola y = - X & # 178; - 6x is a straight line x = - 3, and the maximum value of function is 9