[tex]3x-9y=9[/tex] Equation
[tex]-9y=-3x+9[/tex] Subtract 3x from both sides
[tex]y= \frac{1}{3}x-1 [/tex] Divide by -9 on both sides
[tex]3x- 9( \frac{1}{3}x-1)=9[/tex] Plug in for y
[tex]9=9[/tex] Distribute -9 into the ( ) and simplify
[tex]3y=x+12[/tex] Equation
[tex]y= \frac{1}{3}x+4 [/tex] Divide by 3 on both sides
[tex]3( \frac{1}{3}x+4)=x+12[/tex] Plug in for y
[tex]x+12=x+12[/tex] Simplify
[tex]2x-6y=12[/tex] Equation
[tex]-6y=-2x+12[/tex] Subtract 2x from both sides
[tex]y= \frac{1}{3}x-2 [/tex] Divide by -6 on both sides
[tex]2x-6( \frac{1}{3}x-2 )=12[/tex] plug in for y
[tex]2x-2x+12=12[/tex] Distribute -6 into the ( )
[tex]12=12[/tex] Simplify