While Brendan is vacationing with his family at the cabin, they take a motorboat on the river. The motorboat travels 18 miles per hour in still water. a. Let w represent the speed of the river current in miles per hour. Write an expression for how fast the motorboat is able to go downstream (with the current) Write another expression for how fast the motorboat is able to go upstream (against the current).

b. The motorboat travels 49 miles upstream in the same time it takes to travel 77 miles downstream. What is the speed of the current w? Use the Elimination Method to solve.

c. Could you have used the Equal Values Method or the Substitution Method to solve this problem? Explain. (You do not actually solve using these two methods.)