Answer:
Step-by-step explanation:
12. 15 (3x5x1)
13. 8 (4x2x1)
14. 18 (6x3x1)
The bookshelf would be 4 feet 3 inches.
Step-by-step explanation:
for any matrix multiplication number of columns of first matrix should be equal to number of rows of second matrix.
For AB
A has 3 columns and B has 3 rows so it matches . Hence can be multiplied.
For BA
B has 2 columns and A has 2 rows it also matches so can be multiplied