First, look at the x axis (this is the one labeled Minutes Used per month)
Find the number 40, then look at where the lines meet on that line. The red line for Plan B it’s at 8 dollars. The blue line for Plan A is at 4 dollars.
Plan B costs more.
To find the difference, subtract 4 from 8.
$8 - $4 = $4
Plan B costs 4 dollars more than Plan A.
If you have any further questions feel free to ask.
Hope this helps.
An excluded value is one where the bottom of the fraction = 0.
In your case 1-3x=0
1=3x
x=1/3
At this point, the function does not exist. If you were to draw a graph of it, there wouldn't be a y-value corresponding to x=1/3.
found this online, hope it helps !!