Hi there!
When you answer a math problem with 2 variables, you have to make sure the other is in your answer. :)
Solve for x -
Step 1) Add -6y to both sides.
3x + 6y + -6y = 18 + -6y
3x = -6y + 18
Step 2) Divide both sides by 3.
3x/3 = -6y + 18/3
x = -2y + 6
Final Answer -
x = -2y + 6
Hope this helps!
If you need anything else, send me a message! I'd be happy to help! :D