Answer:
wait what?
Step-by-step explanation:
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
Answer:
(x+6)(x-6)
Step-by-step explanation:
Given: x²-36
Difference of Squares Formula: x²-a²=(x+a)(x-a)
Since 6²=36: x²-6²=(x+6)(x-6)
Answer:
11=h
11 hours of work
Step-by-step explanation:
350=30h+20
subtract 20 from each side
330=30h
divide by 30 to each side
11=h
