Hallo! :D
In the last problem you asked and I answered, it had said that if we had a math problem with two variables, and we only solve for one, the other will end up in our answer.
Step 1) Add -3x to both sides.
\(3x + 6y + -3x = 9 + - 3x 6y = -3x + 9\)
Step 2) Divide both sides by 6.
\(\frac{6y}{6} = \frac{-3x + 9}{6}\)
\(Y = \frac{-1}{2} x + \frac{3}{2}\)
Final Answer -
\(Y = \frac{-1}{2} x + \frac{3}{2}\)
Hope this helps! :D