Answer:
26 dimes are worth $2.60, and 12 nickels are worth $0.60. $2.60 plus $0.60 is $3.20.
Step-by-step explanation:
Let N represent the number of nickels. Let D represent the number of dimes. Each nickel is worth 5 cents, so the value of the nickels in cents is . Likewise, the value of the dimes is cents. Finally, the total amount of money is $3.20 which is the same as 320 cents. Putting it all together you have:
N + D= 38
5N + 10D= 320
If you solve the first equation for in terms of you get:
N = 38 - D
giving you an expression involving that is equal to and that can be substituted in place of in the other equation.
5( 38 - D) + 10D= 320
Now solve for D .
190 - 5D = 320
190 + 5D = 320
5D = 320 - 190 = 130
D= 26
So there are 26 dimes and therefore there must be 12 nickels.