Let matrices A, B, C, and D be of orders 4 × 8, 2 × 8, 8 × 4, & 2 × 4. Determine whether the matrices are of proper order to perform the operation. Give the order of the answer.

Question

(If not possible, enter IMPOSSIBLE.)

(BC − D)A

= ______ x ______

Answer 1

Remember, multiplication of matrix is not commutative. The number columns of the first matrix should be the same as the number of rows of the second matrix so you can multiply them. This is how to determine the size of the resulting matrix.

BC = (2 x 8) (8 x 4) = (2 x 4)

For addition and subtraction of two matrix, they should have the same size

BC -D = (2 x 4) - (2 x 4) = (2 x 4)

(BC - D)A = (2 x 4) (4 x 8) = (2 x 8)

Therefore it is possible and the size of (BC-D)A is (2 x 8).