PLEASE PLEASE PLEASE HELP WITH PART B

Which is equivalent to 10/12? options: 10/18 5/6 3/12 9/11

In which direction does the left side of the graph of this function point? a(x) = 3x - x2 + 4x - 2

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%)