2mn−1 m2\frac{2 \mathrm{mn}-1}{\mathrm{~m}^{2}} m22mn−1
1−2mnm2\frac{1-2 m n}{m^{2}}m21−2mn
2n−1m2\frac{2 n-1}{m^{2}}m22n−1
1−2nm2\frac{1-2 n}{m^{2}}m21−2n