Answer: the speed of the current is 9 mph.
Step-by-step explanation:
Let x represent the speed of the current.
A boat can travel 21 mph in still water. If it travels 270 miles with the current. It means that the total speed with which the boat travelled with the current is (21 + x) mph.
Time = distance/speed
Time spent by the boat in travelling 270 miles is
270/(21 + x)
In the same length of time, it travels 108 miles against the current. It means that the total speed with which the boat travelled against the current is (21 - x) mph.
Time = distance/speed
Time spent by the boat in travelling 108 miles is
108/(21 - x)
Since the time is the same, then
270/(21 + x) = 108/(21 - x)
270(21 - x) = 108(21 + x)
5670 - 270x = 2268 - 108x
108x + 270x = 5670 - 2268
378x = 3402
x = 3402/378
x = 9
Answer:12cm
Step-by-step explanation:3+3+3+3 because its 3x3 so their is 3cm on each side
Answer:
So, the relation between variables are

Step-by-step explanation:
We are given

Since, we have to find relation between variables
so, we can solve for y

Firstly, we will multiply both sides by y

we can simplify it

we can isolate y
so, we can divide both sides by 7
so, we get

Answer:
i think the answer is C. 1/2
Answer:
3.2t - 2.4
Step-by-step explanation:
Given
- 3.6 - 1.9t + 1.2 + 5.1t ← collect like terms
= (- 1.9t + 5.1t) + (- 3.6 + 1.2)
= 3.2t + (- 2.4)
= 3.2t - 2.4