Question

If U = [2, – 3, 4], V = $\begin{bmatrix} 3 \\ 2 \\ 1 \end{bmatrix}$, X = [0, 2, 3] and

Y = $\begin{bmatrix} 2 \\ 2 \\ 4 \end{bmatrix}$, then UV + XY =

• A. 20
• B. [–20]
• C. –20
• D. [20]

Answer 1

Answer: (D)

$20$

Answer 2

U = [2 –3 4]

V = $\begin{bmatrix} 3 \\ 2 \\ 1 \end{bmatrix}$, X = [0 2 3], Y = $\begin{bmatrix} 2 \\ 2 \\ 4 \end{bmatrix}$

Then U.V + X. Y = [2 –3 4]. $\begin{bmatrix} 3 \\ 2 \\ 1 \end{bmatrix}$ + [0 2 3] $\begin{bmatrix} 2 \\ 2 \\ 4 \end{bmatrix}$

= [6 – 6 + 4] + [0 + 4 + 12]

= [4] + [16] = [20]