Linear Algebra - Linear Combinations Question

Question

Hello Everybody I'm a beginner at Linear Algebra and came across a question where I have two possible answers. I just want to know which answer is the right one.

So the question is given the following vectors compute the linear combination below:

$$ u = \begin{bmatrix}5 \\ -1\end{bmatrix} \qquad v = \begin{bmatrix} 8 \\ -1\end{bmatrix}$$

$-4u - 2v = ?$

So my answers are either [-36,6] or [-4, 2] which one would be right?

Answer 1

You wanted to find $$ -4u - 2v$$ where$$ u = \begin{bmatrix}5 \\ -1\end{bmatrix} \qquad v = \begin{bmatrix} 8 \\ -1\end{bmatrix}$$

So the correct answer is $$\begin{bmatrix}-36\\ 6\end{bmatrix}$$ which may be written as $$ [-36,6]^T$$ as well.