Question:
For the following matrices, verify that $A(B C)=(A B) C$ :
$A=\left[\begin{array}{lll}1 & 2 & 5 \\ 0 & 1 & 3\end{array}\right], B=\left[\begin{array}{ccc}2 & 3 & 0 \\ 1 & 0 & 4 \\ 1 & -1 & 2\end{array}\right]$ and $C=\left[\begin{array}{l}1 \\ 4 \\ 5\end{array}\right]$
Solution:
