18/1
36/2
72/4
...and many more....
Step-by-step explanation:

Alright so I got A=4, B=5 and C=9
A B C
+ A C B
----------
C B A
459
+ 495
--------
954
Since there is a right angle, you can use Pythagoras' Theorem:
So x = √(24² + 7²) = 25
---------------------------------------------------------
Answer:
25