x=6.
Because you divide both sides by 3 to isolate x.
(Please tell me this is right/wrong.)
This is right!
If you are ever unsure of an answer you get algabraically, you can substitute in into the original equation and see if the equation hold true. Remember, you got x=6.
\(3*6=18\)
\(18=18\)
18=18, after all. This means that your answer is correct.