)find the coordinates of the points of intersection of the parabola y _ = -x 2 + 9 .x -3 and the line y = 3 x.

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%)