I NEED HELP FAST OR I WIL FAIL What is the approximate solution to the system of equations? y=x+1, y=3x (-.33, -1.33) (1.4, 2.5) (-.67, .25) (0, 1.5)

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%)