I didn't understand well the way you typed but I think that it is 7/3x + 2/x + x/x-1 , right? So the last common denominator is the one you can divide by all denominators and multiply by the nominator. So, it would be, if I understood well what you asked, 3x(x-1).
1st; t+u=10 2nd: t-u=6 Add 1st and 2nd and solve for t,as follows: 2t = 16 t = 8 Substitute in t+u=10 to solve for u: 8+u=10 u = 2 Original Number = 82</span>
