Please give me an answer

Question

A company manufactures and sells mini-recorders. A survey of office supply stores indicated that at a price of $60 each, the demand would be three hundred recorders, and at a price of $30 each, the demand would be eight hundred recorders. If a linear relationship between price and demand exists, which of the following equations models the price-demand relationship?

(Let x represent the price per mini-recorder and y represent the demand in hundreds.)

 A. 

 B. 

 C. 

 D. 

Answer 1

The first step in translating a proper relationship here would be properly writing out the information you have in the paragraph into usable numbers to assess. if X is the price and Y is the demand in HUNDREDS, then our functional point sets would be (30,8) and (60,3). By realizing that, we can determine immediately that A or C would not be valid choices. We also know from the relationships to the variable that to get a positive outcome of Y with the negative slope we need a positive constant to be added. With that information, we could remove choices C and D from possible choices. The ending result is knowing that B has to be correct which is proven when you take -1/6 X 30 to get -5, which is then added to 13 to result in 8.