Chapter 8.1, Problem 4E

In Exercises 1–4, write y as an affine combination of the other points listed, if possible.

4. $v_1=\left[\begin{array}{c}1\\ 2\\ 0\end{array}\right]$, $v_2=\left[\begin{array}{c}2\\ -6\\ 7\end{array}\right]$, $v_3=\left[\begin{array}{c}4\\ 3\\ 1\end{array}\right]$, $y=\left[\begin{array}{c}-3\\ 4\\ -4\end{array}\right]$