Which of the following is equal to square root of 16*4?
pls see the pic below.

Which of the following parabolas opens up?

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 value of the variable and the length of each chord for #5 and #6.