Question

A motorboat travels 9 miles downstream (with the current) in 30 minutes. The return trip upstream (against the current) takes 90 minutes.

Which system of equations can be used to find x, the speed of the boat in miles per hour, and y, the speed of the current in miles per hour? Recall the formula d = rt.

Answer 1

Explanation:

I don't know what systems you have to choose , but a system is:

18 = x+y

6 = x-y

x=12

y=6

so the boat moves at 12 miles per hour and the stream moves at 6 miles per hour

Answer 2

The system of equation that can be used will be linear equation.

Explanation:

Let it can be written as

18 = x+y

6 = x-y

so after calculation we can get value of x and value of y

x=12

y=6

Hence the boat moves at 12 miles per hour ,and the stream moves at 6 miles per hour.