SOLUTION: I am hoping you could help me with a problem I have with solving application problems using two variables with linear systems. A whale swimming against an ocean current trave

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Question 135044This question is from textbook Essentials of Elementary Algebra
: I am hoping you could help me with a problem I have with solving application problems using two variables with linear systems.

A whale swimming against an ocean current traveled 60 miles in 2 hours. Swimming in the opposite direction, with the current, the whale was able to travel the same distance in 1.5 hours. Find the speed of the whale in calm water and the rate of the ocean current.

I know the answer is the rate of the whale in calm water is 35mph. The rate of the current is 5mph. (From out of the book.) However, I not sure how to do the equations in order to get those answers.

I think its something like:
2=60+x 1.5=60-x
Thank you so much for trying to help me!
This question is from textbook Essentials of Elementary Algebra

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
You're on the right track. But you need to establish the relationship between distance, time and speed.
distance+=+rate%2Atime
The distance the whale swims is the same going both directions.
The rate changes based on swimming with or against the current
Let the calmspeed = x and the current =y
RateWith = calmSpeed+Current = x+y
RateAgainst = calmSpeed-Current = x-y

So
60+=+%28x%2By%29%2A1.5 with current
60+=+%28x-y%29%2A2 against current
So
60+=+%28x-y%29%2A2
30+=+x+-+y
30+%2B+y+=+x remember this for later

60+=+%28x%2By%29%2A1.5
40+=+x+%2B+y
use the value for x we found above to get 40+=+%28%2830+%2B+y%29+%2B+y%29+
10+=+2y
5+=+y
x = 30+5 = 35