Answer variants:
Verify the associative property \((A + B) + C = A + ( B + C)\) of the given matrices.
\(A = \begin{bmatrix}
9 & 5 & -3\\
5 & 9 & 12\\
4 & 2 & 9
\end{bmatrix}, B =\begin{bmatrix}
5 & 12 & 8\\
13 & 5 & 3\\
9 & 11 & 3
\end{bmatrix}, C =\begin{bmatrix}
6 & 4 & 6\\
7 & 5 & 3\\
4 & 1 & -11
\end{bmatrix}\)
9 & 5 & -3\\
5 & 9 & 12\\
4 & 2 & 9
\end{bmatrix}, B =\begin{bmatrix}
5 & 12 & 8\\
13 & 5 & 3\\
9 & 11 & 3
\end{bmatrix}, C =\begin{bmatrix}
6 & 4 & 6\\
7 & 5 & 3\\
4 & 1 & -11
\end{bmatrix}\)
| \(A + B\) | \(=\) |
| \((A + B) + C\) | \(=\) |
| \(B +C\) | \(=\) |
| \(A + (B + C)\) | \(=\) |
The associative property of the matrix \((A + B) + C\) \(A + ( B + C)\)