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alisha [4.7K]
3 years ago
6

Jeff has $1.35 in nickles and dimes. He has a total of 15 coins. How many of each coin does he have?

Mathematics
1 answer:
dlinn [17]3 years ago
4 0

For this case we propose a system of equations.

We know that a dime equals 10 cents and a nickel equals 5 cents.

So:

x: Let the variable that represents the number of dimes

y: Let the variable that represents the number of nickels

According to the statement we have:

x + y = 15\\0.10x + 0.05y = 1.35

We multiply the first equation by -0.10:

-0.10x-0.10y = -1.5

We have the following equivalent system:

0.10x + 0.05y = 1.35\\-0.10x-0.10y = -1.5

We add the equations:

0.10x-0.10x + 0.05y-0.10y = 1.35-1.5\\-0.05y = -0.15\\y = \frac {-0.15} {- 0.05}\\y = 3

So, Jeff has 3 nickels

x + y = 15\\x + 3 = 15\\x = 15-3\\x = 12

Jeff has 12 dimes.

Answer:

12 dimes and 3 nickels

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