Determine graphically the x-value when y
equals
=
2
2 in the given equation.

negative x plus 2 y equals 8
−x+2y=8

This problem is very simple. Knowing that y=2, plug 2 into the "y" in the equation: -x+2(2)=8

-x+4=8 
subtract 4 on both sides of the equation:
-x=(8-4)
-x=4
Divide both sides of the equation by (-1):
x=(-4)