Answer:
X=6
Explanation:
You want to get x by itself on one side, This way, it says x=something. You want to do the inverse operation to get the three to the other side. Right now it is multiplication, so you would do division. you do -18 / 3. When you do this you get -6. your equation now looks like this: x=-6.
That is your answer. I hope this helped!