In the year 2005, the average cost of a car could be modeled by the equation C= -15x^2 + 20x - 3 where x is the number of years since 2005. By the year 2010 the average cost had changed, and the equation could be modeled by C= -10x^2 + 30x - 2. Find the difference in average cost equation for cars between 2005 and 2010.

How is working backward similar to solving an equation?

How much money does ron have left each month after his fixed expenses? ron graduated from college five years ago. he recently bought a house, but shares it with a housemate who pays him $800 a month for rent and utilities. ron is putting a budget worksheet together so he will have a better idea of where his money is going and where he can save. enlarge

The table shows the distances travelled by a paper aeroplane. a. find the range and interquartile range of the data. the range is feet. the interquartile range is __feet. b. interpret the range and interquartile range of the data. __ feet the distances travelled by the paper aeroplane varied by no more than__ feet. the middle half of the distances travelled by the paper aeroplane varied by no more than __ feet.