You begin a hike in death valley, california at an elevation of -86 meters. you have to a point of elevation at 45 meters. what is your change in elevation?

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%)