Find the missing number (?) in the following mathematical pattern:

Let us analyze the mathematical relationship between the numbers in each pattern cluster:
$$\text{Top-Left Number}-\text{Top-Right Number}-\text{Bottom Number}=\text{Middle Number}$$

Let us verify this logic across the given figures:

* First Pattern:

$$93-27-3=66-3=63$$

This matches the middle number ($63$).
* Second Pattern:

$$79-38-4=41-4=37$$

This matches the middle number ($37$).
*Third Pattern (with the missing number $x$):**

$$67-16-x=42$$

$$51-x=42$$

$$x=51-42=9$$

Thus, the missing number is 9.