I translated this as "He uses the theory for the solution," which I think is disgustingly loose -- should be "to find the solution." Is this sentence equally bad in Esperanto?
No, it isn’t. I do not think that it is necessary to use trovi unless you want to start a philosophical discussion whether you find an existing, but unknown or hidden solution, or whether you create a new solution that has not existed before.
"To find a solution / por trovi solvon" perhaps.
Patricia, I agree with you. I was going to make the same comment myself.
Can "solvo" be used as solution ( a mixture in a liquid form) as in most languages? For example: segnoro Jekyll trinkis la solvo kaj li transformiĝis en segnoro Hyde.
Sinjoro Jekyll trinkis solvaĵon kaj transformiĝis en sinjoron Hyde.