Let $\mathbf{A}=\left(\begin{array}{cc}1 & 2 \\ 0 & -1\end{array}\right)$ And $\vec{u}=(5,-1)$ Find $\vec{w}$

Short Answer

Let $\mathbf{A}=\left(\begin{array}{cc}1 & 2 \\ 0 & -1\end{array}\right)$ and $\vec{u}=(5,-1)$ . Find $\vec{w}$ such that $\vec{u}=\mathbf{A} \cdot \vec{w}$ .