Question 56680
solve by graphing.
L1) x-y=2
L2) 3x-3y=6
:
For L1)
Let x=0 and solve for y, this is your y-intercept:
0-y=2
-y=2
-(-y)=-(2)
y=-2
Plot (0,-2)
Let y=0 and solve for x, this is your x-intercept:
x-(0)=2
x=2
Plot (2,0)
Connect the dots and you have a line that looks like:
{{{graph(300,200,-10,10,-10,10,x-2)}}}
For L2)
Let x=0 and solve for y, this is your y-intercept of this line:
3(0)-3y=6
-3y=6
-3y/3=6/-3
y=-2 
Plot (0,-2)  Notice that is the same y intercept that L1) had:
Let y=0 and solve for x, this is your x-intercept:
3x-3(0)=6
3x=6
3x/3=6/3
x=2
Plot (2,0)  Notice that is the same x-intercept that L1 had.  L1 is lying right ontop of L2, in other words they graphically are the same line.  The solution is all real numbers:
{{{graph(300,200,-10,10,-10,10,x-2,(-3x+6)/-3)}}}
Happy Calculating!!!