When we have an expression and we want to solve for a given variable, in this case x, we need to isolate that variable on the left side of the equation. To do that we will have to switch the other terms from one side to another of the equation. When that's done their operation will be switched, if a term is adding it'll go to the other side by subtracting and if it is subtractiong it will go to the other side adding.
With this in mind lets isolate the "x" variable.
The correct answer is the option C.