If you would like to solve the equation x/m - x/n = 1/p for x, you can do this using the following steps:
x/m - x/n = 1/p
x (1/m - 1/n) = 1/p
x = 1/p / (1/m - 1/n)/1
x = 1/p 1/(1/m - 1/n)
x = 1/(p(1/m - 1/n))
The correct result would be x = 1/(p(1/m - 1/n)).
