Answer:
Let's represent the two numbers as a column vector:
\[ A = \begin{bmatrix} x \\ y \end{bmatrix} \]
The sum of the numbers is 12, so we have the equation:
\[ x + y = 12 \]
The difference between the numbers is 4, so:
\[ x - y = 4 \]
We can represent these equations as a matrix equation:
\[ \begin{bmatrix} 1 & 1 \\ 1 & -1 \end{bmatrix} \begin{bmatrix} x \\ y \end{bmatrix} = \begin{bmatrix} 12 \\ 4 \end{bmatrix} \]
Now, we can use matrix inversion to solve for the vector \([x, y]\). The solution will give you the values of the two numbers Amjad is thinking of.