Was this the ninth year of Hoshe'a's reign?
Rashi: It was the ninth year of his rebellion (Malbim (1) - from when he began to rule independently).
What is the meaning of "va'Yegel"?
Rashi: This is like va'Yagleh (he exiled). Any verb that the last letter of its root is Hei, e.g. Banah, Panah, Galah, Rabah, and one comes to add Vov Yud at the beginning - if it discusses the one who acts, there is Chirik under the Yud, e.g. "va'Yiven Sham Mizbe'ach" (Bereishis 12:17), "va'Yifen va'Yered Moshe" (Shemos 32:15), "va'Yigel Yehudah me'Al Admaso" (25:21)
Where are these places to which he exiled them?
Mar Zutra (Sanhedrin 94a): They are in Africa.
R. Chanina (Sanhedrin 94a): They are in Harei Selug. Chidushei Agados Maharal - these are Harei Shelug (snowy mountains) far from civilization.
