Knowing that the vertex form of the quadratic equation is y=a(x-h)^2+k where (h,k) represents the vertex, and the a value represents the leading coefficient of the quadratic equation in standard form, first plug in your known values (your given coordinate point can be plugged into the x and y values, and your given vertex can be plugged into h and k): -4=a(0-10)^2-9
Because your a value is still unknown, you can use your given values in the equation to solve for a: -4=a(-10)^2-9 -4=100a-9 100a=5 a=1/20
Now that you have your a value, you can plug it into your vertex form as well as your vertex values to get that your equation in vertex form is: y=1/20(x-10)^2-9
