Question:
If $\boldsymbol{A}=\left(\begin{array}{ccc}1 & -2 & 0 \\ 2 & 1 & 3 \\ 0 & -2 & 1\end{array}\right)$ and
$B=\left(\begin{array}{ccc}7 & 2 & -6 \\ -2 & 1 & -3 \\ -4 & 2 & 5\end{array}\right)$, find $A B$
Hence, solve the system of equations:
$x-2 y=10$
$2 x+y+3 z=8$ and
$-2 y+z=7$
HINT: $A B=(11) /=A\left(\frac{1}{11} B\right)=I$
$A^{-1}=\left(\frac{1}{11}\right) B$
Solution:
