− 4 u 2 v 2 − 7 u 2 v + 3 u 2 − 7 u v 2 + 13 u v − 7 u + 3 v 2 − 7 v + 4 u v {\displaystyle -{\frac {4u^{2}v^{2}-7u^{2}v+3u^{2}-7uv^{2}+13uv-7u+3v^{2}-7v+4}{uv}}}
