Question 455785
There are 23 coins in a bank. All the coins are dimes and quarters.
 The total value of the coins is $3.80.
 How many dimes are there?
 How many quarters
:
We can write two equations here
total coins
d + q = 23
put this in the form for substitution
d = (23-q)
and value equation
.10d + .25q = 3.80
now substitute (23-q) for d in the above equation solve for d, then find q