It looks to me like substitution is the best method for solving this system. To do that, I can isolate x on the first equation and substitute its expression for x in the second equation:
x - 2y = 6 x = 2y + 6
Now substitute into the second equation:
3(2y + 6) = 18 6y + 6 = 18 6y = 12 y = 2
Substitute the value for y into the first equation to find x:
x - 2(2) = 6 x -4 = 6 x = 10
Finally, substitute both values into both original equations to check work:
