Answer
a) $\left[ {\begin{array}{cc}
5\\
1
\end{array} } \right]$
b) $\left[ {\begin{array}{cc}
-1\\
4
\end{array} } \right]$
Work Step by Step
We want to compute $u+v$ and $u-2v$ for $u= \left[ {\begin{array}{cc}
3\\
2\\
\end{array} } \right]$ and $v= \left[ {\begin{array}{cc}
2\\
-1
\end{array} } \right]$.
$u+v=\left[ {\begin{array}{cc}
3\\
2\\
\end{array} } \right]+\left[ {\begin{array}{cc}
2\\
-1
\end{array} } \right]=\left[ {\begin{array}{cc}
5\\
1
\end{array} } \right]$
$u-2v=\left[ {\begin{array}{cc}
3\\
2\\
\end{array} } \right]-2\left[ {\begin{array}{cc}
2\\
-1
\end{array} } \right]=\left[ {\begin{array}{cc}
-1\\
4
\end{array} } \right]$
