To solve this problem, we need to find the element $b_{23}$ in matrix $B$. Since matrix $A$ is given as equal to matrix $B$, the corresponding elements in both matrices are identical. Therefore, $b_{23}$ will be the same as the element in the 2nd row and 3rd column of matrix $A$.

Matrix $A$:

$A = \begin{bmatrix} 2 & 0 & -9 & 11 \\ 18 & -7 & 0 & 21 \end{bmatrix}$

From this matrix:

• The element in the 2nd row and 3rd column is 0.

Answer

The value of $b_{23}$ is 0.

Would you like more details or have any questions?

Here are some follow-up questions you might find useful:

1. What is a matrix and how are elements identified by their positions?
2. How can we determine the size (dimensions) of a matrix?
3. What does it mean for two matrices to be equal?
4. How do you extract specific elements from a matrix?
5. What are common operations with matrices (e.g., addition, multiplication)?

Tip: When identifying elements in a matrix, remember that the first index denotes the row, and the second index denotes the column.