3 sisters are each 2 years apart in age. the youngest sister is emily, the middle sister is samantha and the oldest sister is lauren. together their combined ages are 42. how old is each sister?
a. define the variable(s).
b. write an equation for this situation using one variable.
c. solve the equation for the ages of the 3 sisters.

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.)