To solve for x, the most important thing you can do is get x all alone on one side. Your first step is to add six on both sides. Your new equation would look like this:
3/4x=9
You would add six on both sides to get rid of six on the side with x on it.
Your next step would be to multiply each side by 4/3. This is because that gets rid of 3/4 on the side with x. So, 4/3 times 3/4 equals one, and 9 times 4/3 equals four.
X=12
To check it, plug 4 in where x would be.
3/4(12)-6=3
9-6=3
3=3