a$.{\displaystyle \underset{k=1}{\overset{12}{}}}k$

b$.{\displaystyle \underset{k=1}{\overset{9}{}}}(5k+3)$

c$.{\displaystyle \underset{k=1}{\overset{5}{}}}{k}^2$

d$.{\displaystyle \underset{n=1}{\overset{8}{}}}(3+n^2)$

e$.{\displaystyle \underset{m=1}{\overset{3}{}}}\frac{3m+3}{5}$

f$.{\displaystyle \underset{j=1}{\overset{3}{}}}(3j-4)$

g$.{\displaystyle \underset{k=1}{\overset{6}{}}}k(3k+7)$

h$.{\displaystyle \underset{n=0}{\overset{4}{}}}sin(\frac{n}{2})$