Algebra help?

Question

The speed of a stream is 5mph. A boat travels 5 miles upstream in the same time it takes to travel 15 miles downstream. What is the speed of the boat in still water?

Answer 1

x = speed in still water
x-5 = speed upstream
x+5 = speed downstream
5/(x-5) = 15/(x+5)
15x-75 = 5x +25
10x = 100
x =10 mph

Answer 2

the boat loses 5 mph going up the stream, and gains 5mph going down it, since the stream is running at 5 mph. so, let "S" = the boats speed in still water. heres your two equations.
going upstream- 5= S - 5
going downstream- 15= S + 5
hope that sort of helps, im really not too good at explaining stuff, but just incase you really dont care anyhow, the answer is "the boat goes 10 mph in still water

Answer 3

let x be speed in still water and know the formula d=rt which means distance=rate of speed multiply time
this needs to be in the form d/r = t
now write 5/(x-5) = 15/(x+5)
upstream time = downstream time
solve this and get 10=x
so in still water 10 milesperhour

Answer 4

it's all in setting up your problem
time = time
rate - 5 = 5 (upstream)
and
rate +5 = 15 (downstream -with the current)

add 5 to first (both sides)
subtract 5 from second (both sides)

speed is 10 mph

Answer 5

The boat travels at 10mph in still water

Answer 6

river speed = R = 5mph
boat speed = B

distance = rate * time
5 = (B-5)t
15 = (B+5)t
so substitute
t=5/(B-5)
15 = (B+5)*(5)/(B-5)
15 = (5B+25)/(B-5)
B = 10

Answer: 10mph

Answer 7

time = time
15 / (B+5) = 5 / (B - 5) . . . . cancel 5
3 (B - 5) = ( B + 5 )
3 B - 15 = B + 5
2B = 10
B = 5 mph . . . rate of the boat

Answer 8

It would be 10 miles per hour.

Answer 9

very easy 10 mph