The first thing we must do for this case is to define variables. We have then: x = the number of nickels y = the number of dimes z = the number of quarters We write the system of equations: 0.05x + 0.1y + 0.25z = 2.05 x + y + z = 18 x = y Solving the system we have: x = 7 y = 7 z = 4 Answer: nickels = 7 dimes = 7 quarters = 4
