## Precalculus (6th Edition) Blitzer

The expression is $X=\left\{ \left( 1,2,-1 \right) \right\}$
Consider the given system of equations: \begin{align} & 3x-2y+z=-2 \\ & 4x-5y+3z=-9 \\ & 2x-y+5z=-5 \end{align} The linear system can be written as: $AX=B$ $\left[ \begin{matrix} 3 & -2 & 1 \\ 4 & -5 & 3 \\ 2 & -1 & 5 \\ \end{matrix} \right]\left[ \begin{matrix} x \\ y \\ z \\ \end{matrix} \right]=\left[ \begin{matrix} -2 \\ -9 \\ -5 \\ \end{matrix} \right]$ The solution is given by $X={{A}^{-1}}B$; consequently, we must find ${{A}^{-1}}B$ by using a graphic calculator. We will follow the steps given below: (1) Select the matrix $A$ from the matrix edit menu and then enter or accept the dimensions. Next, select the matrix $B$ and enter the elements in the matrix. (2) Use ${{2}^{nd}}$ and press the matrix button. (3) Select the matrix $A$ and use the enter button and then use the function ${{X}^{-1}}$ for multiplication of the matrix. (4) Then use the ${{2}^{nd}}$ button and press the matrix button or select matrix $B$ and press the enter button. (5) Press the enter button to get the value of ${{A}^{-1}}B$. Therefore, X=\left[ \begin{align} & 1 \\ & 2 \\ & -1 \\ \end{align} \right]