(mx+n)/(x^2-1)+(nx-m)/(x^2-1)=(3x-1)/(x^2-1),(mx+n+nx-m)/(x²-1)=(3x-1)/(x²-1)[x(m+n)+(n-m)]/(x²-1)=(3x-1)/(x²-1)∴m+n=3n-m=-1∴m=2n=1