Albert Barnes Commentary 2 Kings 15:30

"And Hoshea the son of Elah made a conspiracy against Pekah the son of Remaliah, and smote him, and slew him, and reigned in his stead, in the twentieth year of Jotham the son of Uzziah." — 2 Kings 15:30 (ASV)

Hoshea, the son of Elah—One of Pekah’s friends, according to Josephus.

The twentieth year of Jotham—According to 2 Kings 15:33 and 2 Chronicles 27:1, Jotham reigned only sixteen years. See also the suggestion in the margin. Strangely enough, this first year of Hoshea is also called, not the fourth, but the twelfth of Ahaz (2 Kings 17:1). The chronological confusion of the history, as it stands, is striking.

Uzziah—That is, Azariah. See 2 Kings 15:1–4.