Is this a math or coding question? How do I prove this?

From text book:

4. In equation (4.10) of CLRS, we see that the product of two matrices can be ex- pressed in terms of the blocks. In this problem, we will prove this property. For- mally, given two n n matrices X = (1 ) and Y-( 311 ), where Ali, A12, A21, A22, BI1, B12, B21, and B22 are n/2 x n/2 submatrices, prove that the product XY can be expressed in terms of these blocks i.e., B21 B22 Solution. Your solution here