Question

You have a total of 21 coins, all nickels and dimes. The total value is $1.70. Which of the following is the system of linear equations that represent this scenario? Let n = the number of nickels and let d = the number dimes.

Answer 1

n = number of nickels

d = number of dimes

1 nickel = 5 cents

1 dime = 10 cents

total number of 21 coins:

n + d = 21

Total value = $1.70

5n + 10 d = 170

Divide by 100

0.05n + 0.10 d = 1.70

Answer:

n + d = 21

0.05n + 0.10 d = 1.70