The simple solution to this apparent contradiction is that Ahaziah was physically 22 years old when he began to reign, but since God has appointed Jehu to cut off the house of Ahab, as a son of Ahab through marriage, he was 42 years old. The information is all there in the texts to the student of the word.
Here are the two passages for those unfamiliar with the issue:
2 Kings 8:26
Two and twenty years old was
Ahaziah when he began to reign; and he reigned one year in Jerusalem. And his mother's name was Athaliah, the daughter of Omri king of Israel.
2 Chronicles 22:2
Forty and two years old was
Ahaziah when he began to reign, and he reigned one year in Jerusalem. His mother's name also was Athaliah the daughter of Omri.
It's plain from the other details that these are talking about the same person.
The second text says plainly, "Forty and two years old". It does not say, "Forty and two years since (some other event)". Nowhere else in Scripture is the phrase, "x years old" used to mean something other than the number of years since a person's
birth. Nobody reading the text would interpret it as anything other than a passage of time from the person's
birth. If someone did say something like, "I was born in 1960; in 1970 I was 25 years old since the end of World War II", people would wonder at that person's intelligence and sanity.
While you can account for the
numbers from a study of other passages, you cannot account for the
wording without this convoluted and ridiculous explanation. You have to reject the plain text, and insert a comically nonsensical explanation, in order to defend your belief in the "perfection" of the KJV text.
Just admit defeat... the KJV is
not perfect. Your life won't end, and since you lean on the faith of Christ and not your own, your relationship with God won't suffer.