A car with 12 gallons of gasoline drives 321 miles until the tank is empty. write a linear equation that describes the amount of gas left in the car, y,after driving x miles

(type the answer in slope intercept form)
use integers or simplified fractions for any number I the expression

The weekly amount spent by a company for travel has an approximately normal distribution with mean = $550 and standard deviation = $40. a) what is the probability that the actual weekly expense will exceed $570 for more than 20 weeks during the next year? (note: one year = 52 weeks) b) what is the probability that actual weekly expenses exceed $580 for 10 or more, but 16 or fewer weeks during the next year?