What is the answer to question 3?

How do you divide 9/4 divided by 10/3

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%)

Find the vertex for the parabola given by the function ƒ(x) = −3x2 − 6x.