Answer
Find out the the rate of the boat in still water.
To proof
let us assume that the speed of the boat in the still water = u
let us assume that the speed of the current = v
Formula
As given
18 miles downstream for 3 hours
Now for the downstream
u + v = 6
now for the upstream
As given
the trip back against the current takes 6 hours
u-v = 3
Than the two equation becomes
u + v = 6 and u - v = 3
add both the above equation
we get
2u = 9
u = 4.5miles per hour
put this in the u - v = 3
4.5 -v = 3
v =1.5 miles per hour
The rate of the boat in the still water is 4.5miles per hour .
Hence proved
Answer:
2
Step-by-step explanation:
lets think of the missing number as x so any number times 10 should equal 20 so x=2
and your equation should look like this--------> 20÷2=10
Answer:
k ≈ 0.1733
Step-by-step explanation:
Using the numbers given, we find the multiplier of the population is 800/200 = 4 in 8 hours. This means the equation of growth can be written ...
y = 200(4^(t/8))
When this is written in the form ...
y = 200·e^(kt)
We can compare the two equations to see that ...
4^(1/8) = e^k
Taking natural logarithms, we have ...
1/8·ln(4) = k ≈ 0.1733
The growth rate k is approximately 0.1733.
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<em>Additional comment</em>
The comparison we were looking for was (4^(1/8))^t = (e^k)^t. Instead of "comparing" the equations, you could set them equal and solve for k.
200(4^(t/8)) = 200e^(kt)
4^(t/8) = e^(kt) . . . divide by 200
t/8·ln(4) = kt·ln(e) . . . . take natural logs
1/8·ln(4) = k . . . . . . use ln(e) = 1 and divide by t
Answer:
0
Step-by-step explanation:
5(x+3) replace x with -3
5(-3+3)
5(0)
0
73 cm I think this is the right answer
