Find the equation, f(x) = a(x-h)2 + k, for a parabola that passes through the point (1,-7) and has (2,- 4) as its vertex. what is the standard form of the equation?

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)