Gio baked 21 cupcakes for the holiday sale. He made some with vanilla icing, and some with mint-chip icing. He charged $2 for the vanilla cupcakes, and $4 for the mint-chip cupcakes and made $54. How many of each did he make? He created the following system of equations to find out how many of each he made. Let x represent the number of vanilla cupcakes, and y represent the number of mint-chip cupcakes.