What is 4 4/5+7 3/5-6

Use the four functions below for this question. compare and contrast these four functions using complete sentences focus on the slope and y- intercept first, and then on any additional properties of each function

If you answer 2+2 you will get over 80 points

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%)