Question

Abby has a jar containing 70 coins, all of which are either nickels or dimes. The total value of the coins in thr jar is $5.60. Let n represent the number of nickels and dimes are in the jar

Answer 1

0.05n + 0.1d = 5.60

d = 70 - n

28 nickels and 42 dimes

Explanation:

1. substitute d = 70 - n in 0.05n + 0.1(70 - n) = 5.60

2. multiply 0.1(70 - n): 7 - 0.1n

3. subtract 7 to the other side of the equation: 0.05n - 0.1n = -1.4

4. subtract 0.1n from 0.05n: -0.05n = -1.4

5. divide -0.05 from n on both sides: n = 28

6. subtract 28 total nickels from the total number of coins: 70 - 28

7. 42 dimes