Question

Sue has $1.80 in dimes and nickels. If she has 9 more dimes than nickels, How many of dimes and nickels does she have?

Answer 1

15 dimes, 6 nickels

Explanation:

D = # of dimes, and N = # of nickels

10D + 5N = 180

D = N + 9

Substitute:

10 (N + 9) + 5N = 180

10N + 90 + 5N = 180

15N = 90

N = 6

D = 15

Answer 2

• 15 dimes
• 6 nickels

Explanation:

Let d represent the number of dimes. Then d-9 is the number of nickels. The total value (in cents) is ...

10d +5(d-9) = 180

15d -45 = 180 . . . . . simplify

d -3 = 12 . . . . . . . . . .divide by 15

d = 15

15 -9 = 6 = number of nickels

Sue has 15 dimes and 6 nickels.