Suppose that the population of a town is described by P=0.6t^2 + 7.2t + 100, where P is the population in thousands and t is the time in years, with t=0 representing the year 2000. in what year(s) is the population 142000

The john nash mall used 17,4000 kilowatt hours in may, with a peak load of 92 kilowatts. the demand charge is $5.95 per kilowatt, and the energy charge is $0.08 per kilowatt hour. the fuel adjustment charge is $0.017 per kilowatt hour. what is the total electricity cost for may?