## Precalculus (6th Edition) Blitzer

The sum of the series is, $\sum\limits_{i=1}^{6}{5i}=105,\sum\limits_{i=1}^{6}{7i}=147,\sum\limits_{i=1}^{4}{2{{i}^{2}}}=60,\sum\limits_{i=1}^{5}{{{i}^{3}}}=225$ and $\sum\limits_{k=1}^{5}{k\left( k+4 \right)}=115$.