At first you have to write the variables out which are

now you have to combine like terms


now you add these two variables and end up with answer of
Answer:
The Natchez tribe lived in the area of St. Catherine's Creek, east and south of the present city of Natchez, Mississippi. Others later settled in South Carolina. The Natchez Indians were successful hunters, fishers and farmers, growing corn, beans, and squash.
Barley. Grains remain an important part of the Russian economy.
Answer:
Areas or regions with low sea level or at sea level are called lowlands.
Lowlands are formed by deposition of lava through water, wind, or soil erosion and it has been said that such plains are more fertile for farming as compared to other high sea-level plains.
At Lowlands, people get opportunities for employment and the economy of the nation can be boosted.
For example, Lowlands of Scotland.
Farmers growing paddy or rice are getting the main benefits of Lowlands.
Lowlands have a suitable environment for many agricultural products.
Farmers can develop dairy farms and mountain farms.