hey I know the formula just don't know what numbers to put where to solve.


Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85. How many dimes does he have?

Nickels = N
Dimes = D

First equation = N + D = $6.05

Second equation = (N - 10) + 2D = $9.85

It is plain sailing from now on.
Take it from here.
Solve it, submit it and we shall have a look at it.

JDReeves

Though Rolcam is correct, note his answer may be confusing also.
With the number of dimes being D and the number of nickels being N, the second equation : (N - 10) + 2D = $9.85 should first be processed.
The 10 reflects the number of nickels, not dollars or cents. So convert the value of 10 nickels first into dollars and adjust the dollar amount at the righthand side.
From there the equations are easy to solve!
Success!