Help me answer the questions relating to a catapult launch

M.xyz =radians. covert this radian measure to its equivalent measure in degrees.

Find the rate of change for the situation.you run 7 miles in one hour and 21 miles in three hours.

Cesar bought 7 items at the candy store. he bought candy bars for $0.50 each and packs of gum for $0.95 each. he spent a total of $6.80. what system represents the solution for the number of candy bars (x) and the number of pack gum (y) purchased?