Find out the missing pattern.

The given pattern involves a series of operations between diagonally opposite numbers within each block to derive a logical conclusion.
Let's analyze the logic in each part of the problem:
After computing the probable and operation steps, the
representing the missing pattern.
concludes logically with the existing block pattern to complete the computational arrangement showcasing all operations used in a congruent and symmetrical manner as per the initial parts.
Find the missing number in the following figure.

Which one will replace the question mark (?) ?

The relationship among the numbers in each corner square is the same as that in the other corner squares. Find the missing number.
Find the missing number.