SOLUTION: A boat can travel 5 miles upstream and 5 miles downstream in a total of 6 hours. If the speed of the current is 2mph, what is the speed of the boat in still water? My progress s

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Question 841096: A boat can travel 5 miles upstream and 5 miles downstream in a total of 6 hours. If the speed of the current is 2mph, what is the speed of the boat in still water?
My progress so far:
D=ER*t
Up: 5 = (x-2) 5/x-2
Down: 5 = ( x+2) 5/x+2
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.T%5B1%5D%2BT%5B2%5D=6
Rate*Time=Distance
%28V%2B2%29%2AT%5B2%5D=5
T%5B2%5D=5%2F%28V%2B2%29
%28V-2%29%2AT%5B1%5D=5
T%5B1%5D=5%2F%28V-2%29
From eq. 1,
T%5B1%5D%2BT%5B2%5D=6
5%2F%28V-2%29%2B5%2F%28V%2B2%29=6
5%28V%2B2%29%2B5%28V-2%29=6%28V%2B2%29%28V-2%29
5V%2B10%2B5V-10=6%28V%5E2%2B2V-2V-4%29
10V=6V%5E2-24
6V%5E2-10V-24=0
3V%5E2-5V-12=0
%283V%2B4%29%28V-3%29=0
Only the positive solution makes sense here.
V-3=0
V=3