Lets say we have a rectangle. if the ratio is 7:5, we can put the width as 7x, and the length as 5x (or vice versa, it doesn't really matter.) If the perimeter is solved by 2(h+w), we have 2(7x+5x)=96, or 2(7x)+2(5x)=96, which is C
Answer:
- 39 quarters and 41 nickels
Step-by-step explanation:
Let the number of quarters be x and nickels be y.
<u>Given:</u>
- Quarter is 25 cents
- Nickel is 5 cents
- Number of coins is 80
- Total amount is $11.80 = 1180 cents
<u>We have equations:</u>
- x + y = 80
- 25x + 5y = 1180
<u>Solve the system by elimination, subtract 5 times the first equation from the second one:</u>
- 25x + 5y - 5x - 5y = 1180 - 80*5
- 20x = 780
- x = 780/20
- x = 39
<u>Find the value of y:</u>
- 39 + y = 80
- y = 80 - 39y = 41
<u>Verify:</u>
- 25*39 + 5*41 = 975 + 205 = 1180
2.5 years = 30 months
7500$ in 30 months
x$ in 1 month
___________________
x = (7500*1)/30 = 250
The answer is 250$/month.
