PLEASE HELP PROPERTIES OF MATRIX OPERATIONS

Suppose  $4\begin{bmatrix} -1 && 2 \\ 4 && 8 \end{bmatrix} = 3/4m X\begin{bmatrix} -1 && 2 \\ 4 && 8 \end{bmatrix}$

and

$(H+\left [1, 4, -2 \right ])+[3, 2, −6] = [−2, 3, −1]+([1, 4,−2]+[3, 2, −6])$

What matrix is the result of m×H ?

(edit: how do i find m and x?? i see each side of the = is similar but what now? I've asked three people and they said they never learned this. im so stuck and i cant move onto my next lesson without it)