18. The current in the Red Cedar River is 6 mph. A canoe can travel 7 miles downstream in the same time that it takes to travel 3 miles upstream when paddled at the same rate. Set up (but do not solve) a rational equation that could be used to find the rate the canoe is paddled, using x as this rate

7/(6 + x) = 3/(6 - x)

Step-by-step explanation:

The current of the Red Cedar River (the speed with which the river is flowing), v = 6 mph

The time it takes the canoe to travel 7 miles downstream = The time it takes the canoe to paddle 3 miles upstream

Let x represent the rate of the canoe, we have;

7/(v + x) = 3/(v - x)

Substituting v = 6 mph, we get the following rational equation, from which the rate of the canoe, x, can be found;

7/(6 + x) = 3/(6 - x).

a is the correct