Let the number of nickels be x Let the number of quarters be y Value Value Type Number of of of of EACH ALL coin coins coin coins ------------------------------------------- nickels x $0.05 $0.05x quarters y $0.25 $0.25y ------------------------------------------- TOTALS 17 ----- $2.65 The first equation comes from the second column.x + y = 17 The second equation comes from the last column. 0.05x + 0.25y = 2.65 Get rid of decimals by multiplying every term by 100: 5x + 25y = 265 So we have the system of equations: . We solve by substitution. Solve the first equation for y: x + y = 17 y = 17 - x Substitute (17 - x) for y in 5x + 25y = 265 5x + 25(17 - x) = 265 5x + 425 - 25x = 265 -20x + 425 = 265 -20x = -160 x = 8 = the number of nickels. Substitute in y = 17 - x y = 17 - (8 y = 9 quarters. Checking: 8 nickels is $0.40 and 9 quarters is $2.25 That's 17 coins. And indeed $0.40 + $2.25 = $2.65 Edwin