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. x+y=21

2x+4y=54

In may you used 400 kilowatt-hours of energy for electricity. a. calculate the total electrical energy use in joules. b. calculate your average power use in watts. c. assume that your power supplier generates electricity by burning oil. note that 1 liter of oil releases 12 million joules of energy. how much oil is needed to generate the electricity you use? give your answer in both liters and gallons. a. the total electrical energy use was nothing _ joules. (type an integer or a decimal.) b. the average power use is nothing _ watts. (round to the nearest whole number as needed.) c. to generate the electricity you used, nothing _ l is needed. (round to the nearest whole number as needed.) to generate the electricity you used, nothing _ gal is needed. (round to two decimal places as needed.)