Answer
$\begin{bmatrix} -4 \\ 6 \\ 1 \end{bmatrix}$
Work Step by Step
In order to subtract two matrices their dimensions must be same.
$D= \begin{bmatrix} 3 \\ 2 \\ 5 \end{bmatrix}-\begin{bmatrix} 8 \\ -4 \\ 6 \end{bmatrix} \\ =\left|\begin{array}{ll}
3-8 \\ 2+4\\5-6 \end{array}\right|\\= \begin{bmatrix} -5 \\ 6 \\ -1 \end{bmatrix}$
Add it to other to obtain: $ \begin{bmatrix} -5 \\ 6 \\ -1 \end{bmatrix}+ \begin{bmatrix} 1 \\ 0 \\ 2 \end{bmatrix}=\begin{bmatrix} -5+1 \\ 6+0 \\ -1+2 \end{bmatrix}= \begin{bmatrix} -4 \\ 6 \\ 1 \end{bmatrix}$
