R = speed in still water
r + c = speed with current
r - c = speed against current
3.5(r + c) = 70
r + c = 20
c = 20 - r
4(r + c) = distance from pier to pier
5(r - c) = distance from pier to pier
4(r + c) = 5(r - c)
4(r + 20 - r) = 5(r - 20 + r)
80 = 10r - 100
180 = 10r
18 = r
The speed in still water is 18 km/hour
Answer:
First option is correct answer.
Step-by-step explanation:
Area = 4x - 10
Perimeter = x + 8
Answer:
Step-by-step explanation:
You are trying to find the value of K, so to do that you need to get k by itself (example : K= 3-5 instead of K+5= 3)
So in 1a i would simplify 7k-3k= 4k
then 4k=11
now to get rid of the 4 and get the k alone- you DIVIDE 4k by 4 and divide 11 by 4 cause you need to do it on both sides of the equation, it should look like this.
4k= 11
- = -
4 4
(4k over 4 and 11 over four)
so the answer is k = 2.75 cause 11/4 = 2.75
Answer: B
Step-by-step explanation:
360 is a full circle. 420-360= 60