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Find the unit rate for: 75% high-fiber chimp food to 25% high -protein chimp food.

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%)

Solve the system of equations. y=3x-1 and y=-2x+9. show work