<span>6 km × 1 hour/(b-4 km) = 12 km × (1 hour/(b+4 km)
6/(b-4) hours = 12/(b+4) hours
6(b+4) = 12(b-4)
6b + 24 = 12b - 48
72 = 6b
b = 12
The boat's speed in still water is 12 km/hour.</span>
9514 1404 393
Answer:
Step-by-step explanation:
The speed against the wind is ...
4680 mi/(8 h) = 585 mi/h
The speed with the wind is ...
5720 mi/(8 h) = 715 mi/h
The speed of the airplane in still air is the average of these speeds:
(585 +715)/2 = 650 mi/h . . . speed in still air
The speed of the wind is the difference between the airplane speed and the speed in the wind:
715 -650 = 65 mi/h . . . speed of the wind
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<em>Additional comment</em>
If p and 'a' represent the speeds of the plane and the air, the speeds with and against the wind are ...
p + a = with
p - a = against
If we average these, we get ...
((p +a) +(p -a))/2 = (with + against)/2
p = (with + against)/2 . . . . . . . the formula we used above
Step-by-step explanation:
To find a solution to this inequality, we need to get 
to one side of the equation by itself. Since we have 
on the left-hand side of the equation, we can get
Answer:
d = 11
Step-by-step explanation:
Isolate the variable (d). Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
First, add 5 to both sides
2d - 5 (+5) = 17 (+5)
2d = 17 + 5
2d = 22
Next, divide 2 from both sides
(2d)/2 = (22)/2
d = 22/2
d = 11
11 is your answer for d.
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Answer:
true
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