Combine scalar multiples of matrices
\(D\) and \(N\) are matrices: \(D\) records the number of pieces of fruit packed into one standard crate at an orchard, while \(N\) records the number packed into one premium crate
In both matrices, the rows are Apples, Pears (top to bottom) and the columns are Tray packs, Loose packs (left to right)
\[D = \begin{bmatrix} 4 & 6 \\ 2 & 5 \end{bmatrix}\]
\[N = \begin{bmatrix} 4 & 4 \\ 5 & 6 \end{bmatrix}\]
An order asks for 5 standard crates and 3 premium crates