− 2 u 2 v 2 − 4 u 2 v + 2 u 2 − 4 u v 2 + 9 u v − 4 u + 2 v 2 − 4 v + 2 u v {\displaystyle -{\frac {2u^{2}v^{2}-4u^{2}v+2u^{2}-4uv^{2}+9uv-4u+2v^{2}-4v+2}{uv}}}