Exercise 4

Decide if the vector is in the column space of the matrix.

• (a)  $\begin{pmatrix}2&1\\ 2&5\end{pmatrix}$, $\begin{pmatrix}1\\ -3\end{pmatrix}$     (b)  $\begin{pmatrix}4&-8\\ 2&-4\end{pmatrix}$, $\begin{pmatrix}0\\ 1\end{pmatrix}$     (c)  $\begin{pmatrix}1&-1&1\\ 1&1&-1\\ -1&-1&1\end{pmatrix}$, $\begin{pmatrix}2\\ 0\\ 0\end{pmatrix}$