Answer:
- rate of the boat in still water = 6.5 miles / hour
- rate of the current = 2.5 miles / hour.
Explanation:
<u>1) Name the two variables:</u>
- b: rate of the boat in still water:
With that, the net rates of the boat down the river and upstrean are:
<u>2) Now set the equations for the distance as a function of the times and the rates:</u>
- downstream: 18 miles = (b + c) × 2 hours
- upstream: 18 miles = (b - c) × 4.5 hours
<u>3) Set the system of equations:</u>
- 18 = 2(b + c) ⇒ 9 = b + c . . . Equation (1)
- 18 = 4.5 (b - c) ⇒ 4 = b - c . . . Equation (2)
<u>4) Solve the system by </u><u>elimination</u><u>:</u>
- Add equations (1) and (2): 9 + 4 = 2b
- Divide both sides by 2: 13/2 = b
- Replace b with 6.5 in equation (2) and solve:
4 = 6.5 - c ⇒ c = 6.5 - 4 = 2.5
<u>5) Results:</u>
- b = rate of the boat in still water = 6.5 miles / hour
- c = rate of the current = 2.5 miles / hour.
For this case we have that the variable "x" represents the number of hours that Leticia uses to take care of children on Saturday.
IF on Friday I use 4 hours ($ 8 each) and on Saturday "x" hours ($ 8 each) obtaining a profit of $ 72, we have the following equation:

We apply distributive property:

So, on Saturday she spent 5 hours.
Answer:

Answer:
approximately 12 payments.
Step-by-step explanation:
you can pay off the loan in a year by multiplying 87.25 and 12. this will give you 1047, which is about 28$ off. then after that year, you can pay off the $28 whenever you finish with the 87.25
Answer:
so if it is asking about the exact percentage then the answer is B but if it is the percentage in all the answer is D.
Step-by-step explanation: My reasoning behind is that 70 percent of the neighborhood wants a playground if it is 40 to 17