Use Inverses to Solve Matrix Equations
- $$\begin{array} { r } 5 x + 7 z = 83 \\9 y + 6 z = 72 \\4 x + 7 y - 2 z = 12\end{array}$$

Multiple Choice

Use Inverses to Solve Matrix Equations
- $$\begin{array} { r } 5 x + 7 z = 83 \\9 y + 6 z = 72 \\4 x + 7 y - 2 z = 12\end{array}$$

A) $\left[ \begin{array} { r r r } 5 & 0 & 7 \\ 0 & 9 & 6 \\ 4 & 7 & - 2 \end{array} \right] \left[ \begin{array} { l } x \\ y \\ z \end{array} \right] = \left[ \begin{array} { l } 83 \\ 72 \\ 12 \end{array} \right]$
B)
$$\left[ \begin{array} { r r r } 5 & 0 & 4 \\0 & 9 & 7 \\7 & 6 & - 2\end{array} \right] \left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { l } 83 \\72 \\12\end{array} \right]$$

C)
$$\left[ \begin{array} { r r r } 5 & 7 & 0 \\9 & 6 & 0 \\4 & 7 & - 2\end{array} \right] \left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } 83 \\72 \\12\end{array} \right]$$
D)

$$\left[ \begin{array} { l l } 5 & 0 \\0 & 9 \\4 & 7\end{array} \right] \left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { l } 7 \\6 \\- 2\end{array} \right]$$