Question 816881
First solve the first equation for y.
2x-y=8
Subtract 2x from each side.
  -y = -2x + 8
Multiply each side by -1
  y = 2x -8
To plot this equation, use the fact that the y
intercept is (0,-8). Since the slope is 2,
beginning at the point (0,-8) move to the right 1
and up 2.  You will now be at the point (1,-6).
Draw a line through (0,-8) and (1,-6).
Now graph the line y=2.  This is just a horizontal
line 2 units above the x axis.
Where the two lines intersect is the solution.

You can check your solution by considering
the two equations
y=2 and y = 2x -8
Set the right hand sides to be equal
and we have
  2 = 2x - 8
Add 8 to each side.
  2 + 8 = 2x - 8 + 8
   10 = 2x
So x = 5.  Of course y = 2 .