Please help! I will love you forever if you do! Select the letter of the correct answer.
Simplify.
7.5 x 10-14
1.5 x 109
5x 10-5
5x1os
5x 10o23
5x10-23

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%)