(a) Show that $\left(\begin{array}{l}4 \\ 0 \\ 1\end{array}\right),\left(\begin{array}{l}2 \\ 1 \\ 0\end{array}\right)$, and $\left(\begin{array}{r}2 \\ -1 \\ 1\end{array}\right),\left(\begin{array}{r}0 \\ 2 \\ -1\end{array}\right)$ are two different bases for the plane $x-2 y-4 z=0$. (b) Show how to write both elements of the second basis as linear combinations of the first. (c) Can you find a third basis?