SOLUTION: m/2+n/2=13/10 3(m-n)=m-10

 = ,        (1)
3(m-n) = m-10.    (2)


Multiply equation (1) by 60 (both sides).  You will get an equivalent equation

30m + 30n = 78.       (1')


Simplify equation (2) step by step. You will get equivalent equations

3m - 3n = m - 10,

2m - 3n = -10,

20m - 30n = -100.     (2')


Now add equations (1') and (2') (both sides). You will get

50 m = 78 - 100 = -22.


Hence, m =  = .


Now from equation (1)   =  =  =  =  = .

Hence,  n =  = .


Answer.  n = ,  m = .