We want to find two things-- the speed of the boat in still water and the speed of the current. Each of these things will be represented by a different variable:
B = speed of the boat in still water
C = speed of the current
Since we have two variables, we will need to find a system of two equations to solve.
How do we find the two equations we need?
Rate problems are based on the relationship Distance = (Rate)(Time).
Fill in the chart with your data (chart attached)
The resulting speed of the boat (traveling upstream) is B-C miles per hour. On the other hand, if the boat is traveling downstream, the current will be pushing the boat faster, and the boat's speed will increase by C miles per hour. The resulting speed of the boat (traveling downstream) is B+C miles per hour. Put this info in the second column in the chart. Now plug it into a formula! <u>Distance=(Rate)(Time) </u>Now solve using the systems of equations!
Given your ordered pair you would assume a = 5, b = 2 Set up both equations 5 + 2 = 7 7 = 7 (the numbers are equal so this correct) 2(5) - 8 = 2 10 - 8 = 2 2 = 2 (the numbers are equal so this is also correct)
Because both equations work with the ordered pair they <em>are</em><span> the solution of the given system.</span>