Does anybody know how to do this?

Shiny white dental insurance costs $258 per year. approximately one-third of insured people need a filling, which averages $110 each. 80% of insured people get a preventive check-up each year, and the average cost of this visit is $95. if you consider shiny white’s income and expenses, what is the expected value of each insured customer?

Find the solution of system of equation y= x-4 y=4x+2

What is the solution of sqrt x+2-15=-3