I really need help with this.
First I had to do a problem that is :
Write an algebraic expression for the total time, in hours, that it takes a jogger to run 2 miles by running 1 mile uphill and then going downhill one mile if the jogger runs uphill at an average speed that is c miles per hour slower than ground level speed of 6 mph and runs downhill at an average speed c more than 6 miles per hour. Simplify your answer to a single algebraic fraction.
36- c squared
I then had to write an expression for the average speed of a jogger running 1 mile uphill and one mile downhill (2 miles total), which turned out to be (and I am POSITIVE these first two are right):
Then, here is the one I am having trouble on:
For what value of c would the jogger's average speed for the two mile trip (one mile up and one mile down) be 4.5 miles per hour? For this value of c, what would be the average rate uphill and downhill?
Thanks for your replies.