Subtract: 2zz2−1−1z+1\frac{2z}{z^2-1} - \frac{1}{z+1}z2−12z−z+11.
1z−1\frac{1}{z-1}z−11
z+1z2−1\frac{z+1}{z^2-1}z2−1z+1
1z2−1\frac{1}{z^2-1}z2−11
z−1z2−1\frac{z-1}{z^2-1}z2−1z−1