I read this equation as 3/(x-3) = 6/8. If that is how you meant it to be, the answer to the question ends up being x = 7. Here's how to get there.
First, multiply both sides by (x-3). That gets you
3 = .75 (x-3)
Multiply out the right side of the equation.
3 = .75x - 2.25
Add 2.25 to both sides and you get
5.25 = .75x
So then you need to divide both sides by .75 to get one side to just be x.
When you do that, you get
x = 7
3/x-3=6/8.To solve for x .
The left side of the equation has two terms separated by a minus operator.
The unknown term is 3/x. Retain it on left and nullify the other numerical term -3 to right side by adding 3 to both sides.
3/x-3+3= 6/8+3. Or
3/x = (6+3*8)/8 =30/8. Taking reciprocal,
x/3 = 8/30. Multiplying by 3 both sides,
x = 8*3/30 = 8/10 = 0.8
Note: 3/x-3 is different from 3/(x-3).