(a) Show that the vectors $\left(\begin{array}{l}1 \\ 1 \\ 1 \\ 0\end{array}\right),\left(\begin{array}{r}1 \\ 1 \\ -1 \\ 0\end{array}\right),\left(\begin{array}{r}1 \\ -1 \\ 0 \\ 1\end{array}\right),\left(\begin{array}{r}1 \\ -1 \\ 0 \\ -1\end{array}\right)$ are linearly independent.
(b) Show that they also span $\mathbb{R}^4$. (c) Write $(1,0,0,1)^T$ as a linear combination of them.