15. Seven days ago, the gas tank on Rosa's car was filled with 20 gallons of gasoline. Today there are 6 gallons of gasoline. a. What integer represents the change of gasoline in the past seven days? b. What is the mean change in gasoline in gallons per day? c. What is the fuel efficiency, in miles per gallon, of Rosa's car if she drove 490 miles in the past seven days?

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

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.)

What is the sum of the measures of the interior angles of an octagon