- #1
karush
Gold Member
MHB
- 3,269
- 5
$\tiny{311.2.2.6}$
Use the inverse to solve the system
$\begin{array}{rrrrr}
7x_1&+3x_2&=-9\\
-2x_1&+x_2&=10
\end{array}$
the thing I could not get here without a calculator is $A^{-1}$
Use the inverse to solve the system
$\begin{array}{rrrrr}
7x_1&+3x_2&=-9\\
-2x_1&+x_2&=10
\end{array}$
$A^{-1}b=x$
$\begin{bmatrix}
\frac{1}{13}&-\frac{3}{13} \\ \\ \frac{2}{13}& \frac{7}{13} \end{bmatrix}
\begin{bmatrix}
-9\\ \\ 10
\end{bmatrix}
=
\begin{bmatrix}
-3\\ \\ 4
\end{bmatrix}$
$\begin{bmatrix}
\frac{1}{13}&-\frac{3}{13} \\ \\ \frac{2}{13}& \frac{7}{13} \end{bmatrix}
\begin{bmatrix}
-9\\ \\ 10
\end{bmatrix}
=
\begin{bmatrix}
-3\\ \\ 4
\end{bmatrix}$
the thing I could not get here without a calculator is $A^{-1}$