Tommy's rowing team needs to row down the stream and then up the stream during the contest. the stream is 10 miles long.

Tommy's rowing team needs to row down the stream and then up the stream during the contest. the stream is 10 miles long. It took his team 2 hours to row down the stream and 3 1/2 hours to row up the stream ( because they are going against the current). let x represent Tommy's team's speed in still water and y be the speed of the current, find both speed. (can you show the work so i can understand it.