Thursday

July 24, 2014

July 24, 2014

Posted by **Rilee** on Friday, November 30, 2012 at 9:56pm.

- Math -
**Reiny**, Friday, November 30, 2012 at 10:44pmlet speed of boat be x mph

time upstream = 1/(x-5)

time downstream = 1/(x+5)

1/(x-5) + 1/(x+5) = 4

multiply each term by (x+5)(x-5)

x+5 + x-5 = 4(x^2 - 25)

2x = 4x^2 - 100

4x^2 - 2x - 100 = 0

x = (2 ± √1604)/8

x = 5.256 or x = a negative, which would make no sense

the speed of the boat in still water is appr 5.26 mph

**Related Questions**

math - a boat travels 4 km upstream and 4 km back. the time for the round trip ...

UPSTREAM - THIS EXURSION WITH A BOAT TRAVEL 35KM UPSTREAM AND THEN BACK AGAIN IN...

math (speed) - A boat cruises downstream for 2 hours before heading back. It ...

math - A boat cruises downstream for 2 hours before heading back. It takes 3.5 ...

math - The speed of a boat in still water is 8 km/h. It travels 60 km upstream ...

math - A boat travels 8km upstream and back in 2 hours. If the current flows at ...

Math - Boat travels 10 mi upstream and 10 mi downstream the stream is moving ...

Algebra - Boat travels 10 mi upstream and 10 mi downstream the stream is moving ...

Math (urgent) hw due tommorow! - The speed of a stream is 3 km/h. A boat travels...

Help...More Math Help!!!...Please! - A kayaker paddled 2 hours with a 6 mph ...