Newspaper: Greenville Journal Length of advertisement: 5 lines
Practice makes perfect
We know that the function for the total cost of advertisement at the Greenville Journal is y=2x+20. For the Daily Times we are given a table with prices for different lengths. We can present all of the given information on a coordinate plane. We can see that the function for the Greenville Journal grows slower, so they charge less per line.
In order to find the number for which the total costs are the same for both newspapers, we have to find their point of intersection. From the graph, we can see that the lines intersects at (5,30). While we know for sure this point lies on the line representing Daily Times, we have to check if the function for Greenville Journal holds true for this point.
The function holds true, so the point (5,30) is the intersection of the functions. Therefore, an advertisement consisting of 5 lines will have the same price in both newspapers.
