Use the graph to state the solution for the system.

x – y = 3 (line a)
x + y = 3 (line b)

a.
(–3, 0)

b.
(0, –3)

c.
(3, 0)

d.
(0, 3)

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%)