A student earns $15 per hour for tutoring and $10 per hour as a teacher's aide. Let x = the number of hours each week spent tutoring and y = the number of hours each week spent as a teacher's aide. Write the objective function that models total weekly earnings.

a technician earns a salary of 37200 plus $40 for each hour of overtime worked. Write a function to model her salary using meaningful variables.

You sell candy at an event to make money.  When candy are sold for $1.10 per bag, approximately 625 bags are sold at each event.  You tried to raise the price to $1.35 and found that the quantity demanded dropped to 525 bags.  The startup cost was $500 and the cost to you per bag of peanuts is $0.50.     Assume that the demand function is linear and write a function that models the profit from selling x bags of peanuts at an event.     What number of bags and what price per bag will get you a maximum profit?

A car initially sold for $23,999. Its class life is 12 years, and the car depreciates by $750 each year. Express this as a linear function. Find the salvage value. Then, find the value after six years.