Why is the solution of the equation 3 / x + 6 / X-1 = x + m / X (x-1) equal to 1 / 2?

Why is the solution of the equation 3 / x + 6 / X-1 = x + m / X (x-1) equal to 1 / 2?

Double x (x-1)
3x-3+6x=x+m
m=8x-3=8*1/2-3
m=1