What is the solution to this system of equations? Two-thirds x + y = 6. Negative two-thirds x minus y = 2.
(1, Negative 1)
(0, 8)
infinitely many solutions
no solution

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%)