### Video Transcript

Given that the matrices 𝐴, 𝐵, and 𝐶 are as specified on screen, find the elements 𝑎 two three, 𝑏 two one, and 𝑐 two one.

The notation 𝑎 subscript 𝑚 subscript 𝑛 refers to the element of the matrix 𝐴 that is in row 𝑚 and column 𝑛. 𝑎 two three is therefore the element in the second row and third column of the matrix 𝐴. The number in this position is nine.

𝑏 two one is the element in the second row and first column of the matrix 𝐵. The number in this position in the matrix 𝐵 is negative six.

Finally, we consider 𝑐 two one. This is the element in the second row and first column of the matrix 𝐶. The number in this position is negative five. The element 𝑎 two three is nine. The element 𝑏 two one is negative six. And the element 𝑐 two one is negative five.