$\ \ Evaluate\ the\ \exp ression:\ \ \ \ \sum_{k=1}^4k^3\$  

 $What\ is\ the\ value\ of\sum_{k=1}^3\frac{k^2}{k+1}$  

 $Evaluate:\ \ \sum_{a=2}^6\left(a^2+a\right)$  

 $Evaluate:\ \sum_{k=-3}^3\left(k^2-k\right)$  

 $Evaluate:\ \sum_{j=-2}^2\left(n^{n+1}\right)$  

 $Find\ the\ sum\ of\sum_{j=1}^5\left(j^2-2^j\right)$