Question

The coordinate grid below shows the graph of supply and demand functions for the sales of a certain video game. For the functions, x

represents the number of video games sold, in thousands of units, and y
represents the price, in dollars, of each game.

The equilibrium point for the supply and demand functions can be found by locating the point where the two functions are equal. Which of these appears to be the number of video games, in thousands, that must be sold to achieve equilibrium?


6

90

8

14

Answer 1

(c) 8

Explanation:

You want the x-coordinate of the point where the lines on the graph cross.

Equilibrium point

The equilibrium point, as the problem statement tells you, is the point where the two lines have the same x- and y-values. That is the point where the lines cross.

The problem statement also tells you that the x-coordinate represent the number of games, in thousands, that will be sold at the price represented by the y-coordinate. By asking for the number of games sold, the question is asking for the x-coordinate of the point where the lines cross.

The lines cross at a grid intersection that is 4 squares right of the y-axis. The label 10 on the 5th square tells you that each square represents 2 (thousands). Hence the x-coordinate of the equilibrium point is ...

8 . . . . . (thousands of games sold)