Defining variables we have: y = the number of dimes x = the number of nickels 0.05x + 0.1y = 0.65 We clear y: y = (- 0.05x + 0.65) / (0.1) y = -0.5x + 6.5 The domain will be: (0, 13) Answer: the domain where and is a function of x is: (0, 13) and the total value is $ 0.65 when x = 1 y = 6