Ineed understanding this and answering this let me know
sc: dalilahmini3

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%)

The height of a plant, in inches, p years after planting it is given by the polynomial function r(p) = -2p% + 270p. find the height of the plant when p = 90 years.

Find the axis of symmerty for x y=x squared -4x-8