Step-by-step explanation: you divide 9.45 by 5 and you get the unit rate of 1.89 and then you divide 13.68 by 8 and you get the unit rate of 1.71 which means the 8 pound bag is cheaper.
First, convert 7 kilometers to meters, which is 7000 meters. Add that to 400, and now you he ran 7400 meters. Now convert 1.6 kilometers to meters, which is 1600 meters. Add that to 7400, and the total is 9000 meters.
