S = d/t
st = d
t = d/s
The time going is t1.
The time returning is t2.
The total time is 4 hours, so we have t1 + t2 = 4
The speed of the current is c.
The speed going is 9 + c.
The speed returning is 9 - c.
t1 = 16/(9 + c)
t2 = 16/(9 - c)
t1 + t2 = 16/(9 + c) + 16/(9 - c)
4 = 16/(9 - c) + 16/(9 + c)
1 = 4/(9 - c) + 4/(9 + c)
(9 + c)(9 - c) = 4(9 - c) + 4(9 + c)
81 - c^2 = 36 - 4c + 36 + 4c
81 - c^2 = 72
c^2 = 9
c^2 - 9 = 0
(c + 3)(c - 3) = 0
c + 3 = 0 or c - 3 = 0
c = -3 or c = 3
We discard the negative answer, and we get c = 3.
The speed of the current is 3 mph.
Answer: it’s the 2nd and Last one
Step-by-step explanation: just got it right
Answer:
Each Friend will get
cards.
Step-by-step explanation:
Let the number of cards be x.
Given:
Amount Nicole used to spend on cards = $9
Total cost of one set =$27
Also, she finds friends with the same amount of money to split the cost of a set.
So, Number of friends she finds can be calculated by dividing the Cost of 1 set with amount of money Nichole used to spend on cards.
Number of friends she finds = 
Hence she finds 2 friends and 1 is nichole hence there are 3 persons carrying $9 to buy $27 set of card
Now, Number of cards each friend gets is equal to Total number of Cards in 1 set divided by number of people.
Number of cards each friend = 
Hence Each Friend will get
cards.
Answer:
B
Step-by-step explanation:
Since QR is the median and it is 12. and NO is 8. 12-8=4.
So I'm going to say 2x+6 will equal 16.
2x+6=16
2x=10
x=5
Solve for n the first can be like:-NP<40+70. -NP<110 the second one can be like : 4w-7k =28. solve for k and then, -7k=28-4w divide both sides by -7 that equal to k =-4-4w