In a coordinate system, if three points (5, 3), (x, 4) and (3, 2) lie on a same line, then find a value of x?

Now, the slope appears to be 1/2 from the two given points.

Does this mean that x will be a number than when used to calculate the slope of the line with any of the other two points will still be 1/2? In this case, 7? Or, do we have to develop the equation of the line and substitute (x,4) into the equation of the line in which case I get 5.