Let the number of nickels be x Let the number of dimes be y Value Value Type Number of of of of EACH ALL coin coins coin coins ------------------------------------------- nickels x $0.05 $0.05x dimes y $0.10 $0.10y ------------------------------------------- TOTALS 36 ----- $2.50 The first equation comes from the "Number of coins" column.x + y = 36 The second equation comes from the "Value of all coins" column. 0.05x + 0.10y = 2.5 Get rid of decimals by multiplying every term by 100: 5x + 10y = 250 So we have the system of equations: . We solve by substitution. Solve the first equation for y: x + y = 36 y = 36 - x Substitute (36 - x) for y in 5x + 10y = 250 5x + 10(36 - x) = 250 5x + 360 - 10x = 250 -5x + 360 = 250 -5x = -110 x = 22 = the number of nickels. Substitute in y = 36 - x y = 36 - (22) y = 14 dimes. Checking: 22 nickels is $1.10 and 14 dimes is $1.40 That's 36 coins. And indeed $1.10 + $1.40 = $2.50 Edwin