Chapter 6.2, Problem 9E

In Exerciser 9-16, find the values of all variables.

$9.\left[\begin{array}{c}2\\ -3\end{array}\right]=\left[\begin{array}{c}x\\ u\end{array}\right]$

$10.\left[\begin{array}{c}-\frac{y}{2}\\ x\end{array}\right]=\left[\begin{array}{c}4\\ 3\end{array}\right]$

$11.\left[\begin{array}{cc}2& x\\ y& -3\end{array}\right]=\left[\begin{array}{cc}2& -1\\ 3& -3\end{array}\right]$

$12.\left[\begin{array}{cc}2-x& 1\\ -2& 3+y\end{array}\right]=\left[\begin{array}{cc}3& 1\\ -2& -3\end{array}\right]$

$13.\left[\begin{array}{cc}2x-3y& -4\\ 5& 3x+y\end{array}\right]=\left[\begin{array}{cc}1& -4\\ 5& 7\end{array}\right]$

$14.\left[\begin{array}{cc}3x+y& -17\\ 19& 2\end{array}\right]=\left[\begin{array}{cc}1& -4\\ 5& 7\end{array}\right]$

$15.\left[\begin{array}{ccc}x-y& 1& 2\\ 4& 3x-2y& 3\\ 5& 6& 5x-10y\end{array}\right]=\left[\begin{array}{ccc}-1& 1& 2\\ 4& -1& 3\\ 5& 6& 6\end{array}\right]$

$16.\left[\begin{array}{ccc}x+y& 2& 3\\ 4& x-y& 4\\ 3& 4& 2x+3y\end{array}\right]=\left[\begin{array}{ccc}-1& 2& 3\\ 2& 5& 4\\ 3& 4& -5\end{array}\right]$