− t 3 + 3 t 2 − 5 t + 7 − 5 t + 3 t 2 − 1 t 3 {\displaystyle -t^{3}+3t^{2}-5t+7-{\frac {5}{t}}+{\frac {3}{t^{2}}}-{\frac {1}{t^{3}}}}
