SOLUTION: reem rowed her boat across lake dukan and back again in 3 hours if her speed coming back was 2km/h less than her speed going and if the distance each way was 7 km find her speed go

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: reem rowed her boat across lake dukan and back again in 3 hours if her speed coming back was 2km/h less than her speed going and if the distance each way was 7 km find her speed go      Log On


   

Question 1101020: reem rowed her boat across lake dukan and back again in 3 hours if her speed coming back was 2km/h less than her speed going and if the distance each way was 7 km find her speed going and her speed coming back
Answer by josgarithmetic(39628) About Me  (Show Source):
You can put this solution on YOUR website!
            SPEED      TIME    DISTANCE

GOING         r        7/r       7

RETURN       r-2       7/(r-2)   7

Total                   3


highlight%287%2Fr%2B7%2F%28r-2%29=3%29
Solve for r and evaluate r-2.
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algebra steps should lead to 3r%5E2-20r%2B14=0;
r=%2820%2Bsqrt%28232%29%29%2F6
r=%2810%2B2%2Asqrt%2829%29%29%2F3
r=%2810%2B10.77%29%2F3
r=6.72------speed GOING
(May need rechecking)