n = number of dimes
21 - n = number of quarters
.10n = value of dimes
.25(21 - n) = value of quarters
.10n + .25(21 - n) = 4.20
Solve for n, number of dimes
21 - n = number of quarters
peer has $4.20 in dimes and quarters. He has 21 coins. How many coins of each kind does he have?
1 answer