Observation: Focusing on the right block that produces \(102\): it is formed from the numbers just below it — \(8\) (to its immediate left in the middle row), and \(6\) and \(4\) in the bottom row — together with the missing value \(x\) in the middle row of that block.
Rule (consistent with this block):
\[
102 \;=\; 8^2 \;+\; (6\times 4) \;+\; x
\]
\(\Rightarrow\ 102 \;=\; 64 \;+\; 24 \;+\; x \ \Rightarrow\ x=102-88=14.\)
\[
\boxed{x=14}
\]