Question

What is 2M?
M=[3 5]
[-4 0]

Answer 1

2M will be:

`2\begin{pmatrix}3&5\\ -4&0\end{pmatrix}=\begin{pmatrix}6&10\\ -8&0\end{pmatrix}`

Therefore, the 2nd option is true.

Explanation:

Given the matrix

`M=\begin{pmatrix}3&5\\ -4&0\end{pmatrix}`

Multiplying by 2 will basically be a scalar multiplication.

Therefore, multiply each of the matrix elements by a scalar.

`2M=2\begin{pmatrix}3&5\\ \:-4&0\end{pmatrix}`

`=\begin{pmatrix}2\cdot \:3&2\cdot \:5\\ 2\left(-4\right)&2\cdot \:0\end{pmatrix}`

`=\begin{pmatrix}6&10\\ -8&0\end{pmatrix}`

Hence, 2M will be:

`2\begin{pmatrix}3&5\\ -4&0\end{pmatrix}=\begin{pmatrix}6&10\\ -8&0\end{pmatrix}`

Therefore, the 2nd option is true.