Amanda has 26 nickels and dimes.
We shall call nickels x and dimes y.
We can write the following equations:
x = 3y -2 or -x +3y = 2
x + y = 26
We can cancel out the x to give 4y = 28 or y = 7
If there are 26 coins in total and 7 of them are dimes then there must be 19 nickels.
The number of nickels (19) is two fewer than three times the number of dimes ( 3(7) - 2 = 19).