Answer:
Let q be the number of quarters in the jar and d be the number of dimes in the jar.
The total number of coins in the jar is given as 54, so we can write:
q + d = 54
The total value of the coins is $16.85. We can express this as the sum of the values of the quarters and the dimes in the jar:
0.25q + 0.10d = 16.85
Therefore, the system of equations that can be used to determine the number of quarters and dimes in the jar is:
q + d = 54
0.25q + 0.10d = 16.85