In order to solve an equation for a certain variable, you should isolate that variable on one side of the equation and leave all the other terms on the other side on the equation.
The, you solve to get the value of the variable.
The equation we have here is:
18−2x=4x
First, we need to isolate the terms containing the "x" on one side of the equation. To do this, we will add 2x to both sides of the equation:
18−2x+2x=4x+2x
18 = 6x
Now, we need to get the value of the "x". To do this, we will simply divide both sides of the equation by 6:
18/6 = 6x/6
3 = x .............> This is the solution of the equation