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8090 [49]
3 years ago
9

Johnny and his father go fishing at 5:00 AM. After motoring 6 km upstream, Johnny writes a letter to his friend, puts the letter

in a bottle and drops it into the river. the bottle floats in the current and reaches at 7 : 40 AM the point where Johnny and his father began the trip. If the speed of the boat in still water is 9 km/h, what is the speed of the river current?
Mathematics
1 answer:
FromTheMoon [43]3 years ago
4 0

Answer:

4.5

Step-by-step explanation:

Probably too late for your RSM homework, but here is the solution:

6/(9-x) [Time they motored upstream] +6/x [Time it took the bottle to get back to the starting point] = 8/3 [Total Time]

Simplify to 54/(x(9-x))=8/3

Cross multiply: 162=(8x)(9-x)

Simplify -x^2+9x=20.25

Multiply both sides by negative one and move 20.25 to the other side. x^2-9x+20.25=0

Solve and get 4.5 :D!

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Answer:

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Step-by-step explanation:

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1/3 = 10/30   1/5 = 6/30   1/2 = 15/30

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yKpoI14uk [10]

Answer:

1.875

Step-by-step explanation:

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Why might algebra tiles not be a good tool to use to factor x2 + 18x + 80?
kvasek [131]
<span>
factor a trinomial to (10+x) (8+x)
 hope it helps</span>
7 0
3 years ago
<img src="https://tex.z-dn.net/?f=%20%5Cfrac%7Bx%7D%7B10.1%7D%20%20%3D%203.5" id="TexFormula1" title=" \frac{x}{10.1} = 3.5" al
dsp73

Answer:

x=35.35

Step-by-step explanation:

If you multiply \frac{x}{10.1} .1 by 10.1 that will cancel out the 10.1s, then since you multiplies one side of the equation by something you have to multiply the other too.  So 3.5*10.1 = 35.35.  Then since the 10.1s canceled out this leaves us with x=35.35.  Let me know if you need any more help.  

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