Answer: x = 1
Step-by-step explanation: When we have this kind of setup, we want to put our variables together on one side of the equation and our numbers together on the other side of the equation.
So first, let's put our variables together on the left side
by subtracting 2x from both sides of the equation.
That gives us 3x + 9 = 12.
Now we can move our numbers to the right by
subtracting 9 from both sides and we get 3x = 3.
Now divide both sides by 3 and x = 1.