As ting posted in the comments in the previous post, the answer is indeed 282. Here’s how to arrive at the answer:
You can basically ignore the bottom three rows and just focus on the top five. I’ve labeled the important blanks with letters so you can use your favorite algebra to solve it.
Let’s start with a, b, c (as always).
From the above, you can derive the following equations:
Based on the above, just simply combine the equations to form:
With a solved, you can easily get the answer for b and c with simple addition. Repeat this with d, e, f and you will arrive at the answer for h=282.
There you go!