Bristol's piggy bank has -16 more dollars than Staci's wallet. If Bristol's piggy bank has $-5, then the amount of dollars in Staci's wallet is modeled by u - 16 = -5 where is u the amount of dollars in Staci's wallet. How much money does Staci’s wallet have?

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%)