Question

Compute each matrix sum or product if it is defined. If an expression is undefined. Explain why. Let A = (3 4 0 -4 -1 4), B = (8 1 -4 -5 2 -4), C = (1 -1 3 1) and D = (3 -2 4 5).
- 2A, B - 2A, AC, CD

Compute the matrix product -2A.

A. -2A =

B. The expression-2A is undefined because A is not a square matrix.

C. The expression-2A is undefined because matrices cannot be multiplied by numbers.

D. The expression 2A is undefined because matrices cannot have negative coefficients.

Answer 1

Answer:

-2A = (-6, -8, 0, 8, 2, -8)

B - 2A = (2, -7, -4, 3, 4, -12)

AC is undefined.

CD = (3, 2, 12, 5)

Step-by-step explanation:

Given the matrices:

A = (3 4 0 -4 -1 4)

B = (8 1 -4 -5 2 -4)

C = (1 -1 3 1)

D = (3 -2 4 5)

We are required to compute the following

-2A, B - 2A, AC, CD

For -2A:

-2(3 4 0 -4 -1 4)

= (-6, -8, 0, 8, 2, -8)

For B - 2A:

Because B - 2A = B + (-2A), we have:

(8 1 -4 -5 2 -4) + (-6, -8, 0, 8, 2, -8)

(2, -7, -4, 3, 4, -12)

For AC:

(3 4 0 -4 -1 4)(1 -1 3 1)

This is undefined.

For CD:

(1 -1 3 1)(3 -2 4 5)

= (3, 2, 12, 5)