The combination reaction that produces aluminum hydroxide from aluminum oxide and water is:

Al₂O₃ (s) + 3H₂O (l) → 2Al(OH)₃ (s)

Here's a breakdown of the reaction:

* Al₂O₃ (s) represents solid aluminum oxide.

* H₂O (l) represents liquid water.

* Al(OH)₃ (s) represents solid aluminum hydroxide.

This reaction is an example of a hydration reaction, where water is added to a compound. In this case, the water molecules react with the aluminum oxide to form aluminum hydroxide.