Let the number of quarters be q Let the number of dimes be d Value Value Type Number of of of of EACH ALL coin coins coin coins ------------------------------------------- quarters q $0.25 $0.25q dimes d $0.10 $0.10d ------------------------------------------- TOTALS 64 ----- $13.60 The first equation comes from the number of coins column.q + d = 64 The second equation comes from the last column. 0.25q + 0.10d = 13.6 Get rid of decimals by multiplying every term by 100: 25q + 10d = 1360 So we have the system of equations: . We solve by substitution. Solve the first equation for d: q + d = 64 d = 64 - q Substitute (64 - q) for d in 25q + 10d = 1360 25q + 10(64 - q) = 1360 25q + 640 - 10q = 1360 15q + 640 = 1360 15q = 720 q = 48 = the number of quarters. Substitute in d = 64 - q d = 64 - (48) d = 16 dimes. Checking: 48 quarters is $12.00 and 16 dimes is $1.60 That's 64 coins. And indeed $12.00 + $1.60 = $13.60 Edwin