Could someone help me please?

Aparallelogram has an area of 216.24 cm2 and a height of 15.9 cm. how long is the base of the parallelogram? enter your answer as a decimal in the box. cm

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?

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?