Question 284253
Let x = Joe's speed in still water

Let y = speed of current

Since there are two things we are solving for, we are looking at a system of linear equations in two variables.


Against Current:

rate = x - y

time = 0.20

distance = 3


0.20(x - y) = 3

0.20x - 0.20y = 3...This is our first equation.

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With Current:

rate = x + y

time = 0.30

distance = 3

0.30(x + y) = 3

0.30x + 0.30y = 3...This is our second equation.

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Here they are together:

0.20x - 0.20y = 3
0.30x + 0.30y = 3

Can you finish now?