Check if \(\displaystyle u\) belongs to the set \(\displaystyle C\):

a. \(\displaystyle u = \begin{bmatrix} -1\\ 2 \\ 1 \end{bmatrix}\) and \(\displaystyle C = \left \{ a\begin{bmatrix} -2\\ 1 \\ 0 \end{bmatrix} + b\begin{bmatrix} 3\\ 0 \\ 1 \end{bmatrix} : a,b \in R \right \}\)

b. \(\displaystyle u = \left ( 1,0,1 \right )\) and \(\displaystyle C = \left \{ a_{1}(2,0,1) + a_{2}(-3,-1,1) : a_{1}, a_{2} \in R \right \}\)