If the solution of the system of equations (m-n) x + y = 5, NX + my = 6 is x = 1, y = 2, find the value of M, n

If the solution of the system of equations (m-n) x + y = 5, NX + my = 6 is x = 1, y = 2, find the value of M, n

X = 1, y = 2 are substituted into the equations
m-n=3
2m+n=6
The sum of the two formulas is as follows:
3m=9
m=3
n=0

Solving the system of equations about XY: mx-y = MX + my = M-1

mx-y=m
y=mx-m=m(x-1) ...(1)
x+my=m-1
x+m*m(x-1)=m-1
x+m^2x-m^2=m-1
(m^2+1)x=m^2+m-1
x=(m^2+m-1)/(m^2+1)
y=m[(m^2+m-1)/(m^2+1)-1]
=m[m^2+m-1-m^2-1]/(m^2+1)
=m^2/(m^2+1)

A and B solve the equations MX + NY = - 8 (1) MX − NY = 5 (2) at the same time. Because a misinterprets m in equation (1), the solution is x = 4Y = 2. B misinterprets n in equation (2), and the solution is x = 2Y = 5. Try to find the correct value of M and n

A misread m in equation (1) and get the solution x = 4Y = 2, so 4m-2n = 5. B misread n in equation (2) and get the solution x = 2Y = 5, so 2m + 5N = - 8. Solve the equations and get m = 38n = -74