Comparison: The slope of this graph is greater but the y-intercept is lower. Graph:
Practice makes perfect
Since it is a linear function, we can write it in slope-intercept form.
y=mx+b
The y-intercept is the point at which x=0. From the table we see that this occurs at y=40. Let's calculate the slope by substituting two points from the table in the Slope Formula.
Now we can write this function in slope-intercept form.
y=0.8x+40
Let's graph it along with the three points in the table in a coordinate plane.
Let's look at the equation from Exercise 38.
c(x)=0.5x+70
Let's add this function to our coordinate plane so that we can compare the two graphs.
Comparing the two functions, we can see that function y has a greater slope but a lower y-intercept than c(x). In other words, the starting fee for this company is lower, but it costs more per hour to rent the truck.
