Answer:
Option B
Step-by-step explanation:
we know that
A line perpendicular to the x-axis is a line parallel to the y-axis
so
the equation of the line is of the form x=(+/-)a
The slope of the line is undefined
where
a is a real number
therefore
x=6 is a line perpendicular to the x-axis
By taking square root of a number using calculator
If the dice is only rolled once, the possibility of getting less than7 is100%
Since we have to solve this system graphically, we'll have to draw both lines.
To draw a line, simply build a little tables with two x,y values: for the first line we have

So, you can draw the points (0,3) and (1,2), connect them, and you'll have the graph of the line 
For the second line we have

So, you can draw the points (0,5) and (1,6), connect them, and you'll have the graph of the line 
Finally, we have to check where the two lines cross. If your drawing is accurate enough, you'll see that the point you're looking for is (-1, 4)