Alvin wants to know what his average paddling rate was for a canoe trip to a campsite. On the way there it took him 7 hours against a river current of 2 km/hr. On the way back, the same distance took him 5 hours with the same 2 km/hr current. Let r= Alvin’s average paddling rate. Express the rates against the current and with the current in terms of r to complete the below table.