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

### Instruction:
 Erin anapanga vitabu vya maktaba ili kuamua ni vingapi vya kubadilisha. Anapata vitabu 8 chini ya mara 6 ya vitabu vilivyoharibika. Ikiwa anatoa vitabu 69 jumla, ni vitabu vingapi vilivyoharibika?


### Response:
 Hebu idadi ya vitabu vilivyoharibika iwe d.
Kisha idadi ya vitabu vilivyopitwa na wakati ni 6d - 8.
Idadi jumla ya vitabu vilivyondolewa ni d + (6d - 8) = 7d - 8 = 69.
Kwa kusuluhisha d tunapata d = 9.
Kulikuwa na vitabu 9 vilivyoharibika.