1)
What is the meaning of "v'Hishlachti Eschem"?
1.
Malbim: I will exile you, like I exiled the 10 tribes.
2)
Who are "Acheichem? Zera Efrayim"?
1.
Rashi: They are the 10 tribes. Radak - they are called Efrayim, because the capitol was in Efrayim on the day that the kingdom was divided. From then and onwards, the 10 tribes were called Efrayim.