__ 18. Given the following matrices, which of these operations is not possible? A=[} 3&-2 4&0 ] a. A+B b. B+A c. CB d. BC

The operation that is not possible is:<br /><br />c. CB<br /><br />Explanation:<br />Matrix multiplication is only possible when the number of columns in the first matrix is equal to the number of rows in the second matrix. In this case, matrix C has 3 columns, while matrix B has 2 rows. Therefore, the multiplication CB is not possible.