− 2 u 2 v 4 − 5 u 2 v 3 + 4 u 2 v 2 + 4 u v 3 − 7 u v 2 + 4 u v + 4 v 2 − 5 v + 2 u v 2 {\displaystyle -{\frac {2u^{2}v^{4}-5u^{2}v^{3}+4u^{2}v^{2}+4uv^{3}-7uv^{2}+4uv+4v^{2}-5v+2}{uv^{2}}}}