From 800–1200, the khmer and mon peoples moved into the northern regions of
a. cambodia.
b. thailand.
c. vietnam.
d. myanmar

The question is asking us to determine the region where moved the Khmer and Mon peoples from 800 to 1200. The Khmers are very old ethnic group that came into Southeast Asia at the same time as the Mon people. They were builders of the Khmer Empire in Cambodia ( 802 - 1431 ). They moved into the northern regions of A ) Cambodia.

343^x = 49^4-xx = 4-xx+x=42x = 4x = 4/2x = 2therefore x = 2