Answer:
![\left[\begin{array}{ccc}-32\\4\\20\\-36\end{array}\right]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yqu6fgpje3iiod9l43h54rqc22au3sc8yr.png)
Explanation:
The product of a scalar times the matrix involves the product of that scalar times each of the elements of the matrix, resulting on the multiplication by "-4" of each of the four elements as shown below. These new product values end up being the new matrix elements.
![-4*\left[\begin{array}{ccc}8\\-1\\-5\\9\end{array}\right] = \left[\begin{array}{ccc}-32\\4\\20\\-36\end{array}\right]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kkr73gr4gc9jq73rokw4lyxe2uwqcff4nm.png)