Answer:

Step-by-step explanation:
The systems of equations are
Let us assume the rate of the current be c
Now actual speed against the current is (15 - c)
And, the actual speed with the current is (15 + c)
Here we applied the time formula i.e. distance by speed
Also the upstream time - downstream time = 4
Now the equations are

Answer:
y=2 over 3x-4
Step-by-step explanation:
I just know pog
Your answer, in your set notation, is
{-2, 7}