Solve these 3 questions 1: 19−4c=17

2: 1.1x+1.2x−5.4=−10

3:The cost C (in dollars) of making n watches is represented by C=15n+85. How many watches are made when the cost is $385?

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?