Find unknown entries in a matrix equation
A school canteen recorded its sales over two weeks. The first matrix below shows the number of each item sold in Week 1, and the matrix on the right-hand side shows the total sold over both weeks. The matrix X records the Week 2 sales
In each matrix, the rows are Sandwiches, Muffins (top to bottom) and the columns are Recess, Lunch (left to right)
\[\begin{bmatrix} 6 & 10 \\ 4 & 11 \end{bmatrix} + X = \begin{bmatrix} 14 & 14 \\ 5 & 15 \end{bmatrix}\]