Answer: OPTION D.
Step-by-step explanation:
The vertex form of a quadratic function is:
Where (h, k) is the vertex of the parabola and "a" is the coefficient of the squared in the parabola's equation.
We know that the vertex of this parabola is at (5,5) and we also know that when the x-value is 6, the y-value is -1.
Then we can substitute values into and solve for "a". This is: