f(x) = - (x + 8)(x - 14)
The zeros (solutions) to the function are -8 and 14.
The vertex lies between these two values. Eleven is the 'x' value of the vertex. To find the y values, plug 11 into the function and solve for y.
f(11) = -(11+8)(11-14)
f(11) = -(19)(-3)
f(11)= - (-57)
f(11) = 57
