Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
Carlson bought land that cost $8000 and additional land that cost $4000. He initially owned 300 square meters of land. If the land he bought costs $20 per square meter, how big is his land after buying the new land?

### Response:
 Carlson alinunua ardhi ambayo inagharimu $20 kwa mita ya mraba, hivyo ukubwa wa ardhi aliyonunua ni 8000/20= <<8000/20=400>>400 mita za mraba.
Na ukubwa wa ardhi nyingine aliyonunua ni 4000/20= <<4000/20=200>>200 mita za mraba.
Hivyo, ukubwa jumla wa ardhi anayomiliki ni 400+200+300= <<400+200+300=900>>900 mita za mraba.