Question 41759
I would put each equation in the slope-intercept format: y = mx + b.
Than graph both equations.  Note their common points.

y = mx + b really means to solve for y.

x - y = 2
-y = -x +2
.
(-1)y/(-1)=-x/(-1) + 2/(-1)
.
y = x - 2
Graph this equation.
.
Solve for y in the second equation:
3x - 3y = 6
-3y = -3x + 6
.
-3y/-3 = -3x/-3 + 6/-3
.
y = x - 2
Graph this equation.

Notice that the equations are the same so they are the same line with all points in common.