en_tn/2ki/10/34.md

are they not written in the book of the events of the kings of Israel?

This rhetorical question can be written as a statement. See how this phrase is translated in 2 Kings 1:18. AT: "they are written in the book of the history of the kings of Israel." (See: rc://en/ta/man/translate/figs-rquestion)

Jehu slept with his ancestors, and they buried him in Samaria

This means that Jehu died. This speaks of him being buried where his ancestors were buried as if he were sleeping with them. AT: "Jehu died and they buried him in Samaria, where they had also buried his ancestors" (See: rc://en/ta/man/translate/figs-euphemism and rc://en/ta/man/translate/figs-metaphor)

Jehoahaz

This is the name of a man. (See: rc://en/ta/man/translate/translate-names)

The time that Jehu reigned over Israel in Samaria was twenty-eight years

"Jehu reigned over Israel in Samaria for twenty-eight years"

twenty-eight years

"28 years" (See: rc://en/ta/man/translate/translate-numbers)