First equation is [tex] x-2y=0 [/tex]
Second equation is [tex] -2x+y=2 [/tex]
subtract equation (2) from (1),
[tex] (x-2y)-(-2x+y)=0-2 [/tex]
Distribute minus inside the paranthesis,
[tex] x-2y+2x-y=-2 [/tex]
Now combine the like terms,
[tex] x+2x-2y-y=-2 [/tex]
[tex] 3x-3y=-2 [/tex]
Thus the value of [tex] 3x-3y [/tex] is [tex] -2. [/tex]
