Solving the equation mnx-n square = mn-m square x with respect to X

Solving the equation mnx-n square = mn-m square x with respect to X

mnx-n^2=mn-m^2x
mx(n+m)=n(m+n)
If M + n = 0, then x can be any real number
If M + n is not equal to 0
Then M and N cannot be 0 at the same time
If M = 0, n is not equal to 0
Then 0 = n (M + n), does not hold and has no solution
If n = 0, M is not equal to 0
Then MX = 0
x=0
If M and N are not equal to 0
Then MX = n
x=n/m