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

### Instruction:
 Kurekebisha tairi moja kunagharimu $7, na ongeza nusu dola kwa kodi ya mauzo. Ikiwa Juan anahitaji kurekebisha matairi yote 4, gharama ya mwisho ni kiasi gani?


### Response:
 Gharama ya kurekebisha matairi yote manne ni 4 * 7 = $<<4*7=28>>28.
Gharama ya kodi ya mauzo kwa matairi yote manne ni 0.50 * 4 = $<<0.50*4=2>>2.
Jumla ya gharama ya kurekebisha matairi yote manne ni 28 + 2 = $<<28+2=30>>30.