Answer:
2 km/h
Step-by-step explanation:
Let x represent the speed of the river current, t₁ be the time spent rowing against the current and t₂ be the time spent rowing with the current.
Since the speed of the still water = 20 km/h.
The speed of rowing against the current = (20 - x)
The speed of rowing with the current = (20 + x)
We know that velocity = distance / time. Hence time = distance / velocity
t₁ = 36 / (20 - x)
t₂ = 22 / (20 + x)
but t₁ + t₂ = 3 hours
Therefore:
3 = 36 / (20 - x) + 22 / (20 + x)
multiply through by 400 - x²
3(400 - x²) = 36(20 + x) + 22(20 - x)
1200 - 3x² = 720 + 36x + 440 - 22x
3x² + 14x -40 = 0
This gives x = -6.7 or x = 2
x cannot be negative therefore x = 2 km/h
The speed of the river current is 2 km/h
x =-5
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1) Since the Formula of the Midpoint is:
2) So Let's plug it into the formula the values, for A, and B
3) So the x coordinate of the Midpoint is x =-5
number is described as rational if it can be written as a fraction (one integer divided by another integer). A number is irrational if it cannot be written as a fraction. The decimal form of an irrational number does not terminate or recur.
D=m-7
d+m=25
m-7+m=25
2m-7=25
2m=32
m=16
d=16-7
d=9
don is 9
