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

### Instruction:
Connor wanted to order some new books to read.  The website was offering free shipping over $50.00.  They also had a deal that when you buy 4 books; the first two were 25% off.  Book 1 cost 13.00 and Book 2 cost 15.00.  Book 3 & 4 were both $10.00 each.  How much more money did Connor need to spend to receive free shipping?

### Response:
 Kitabu cha 1 kilikuwa na bei ya $13.00 na kitabu cha 2 kilikuwa na bei ya $15.00 hivyo 13+15 = $<<13+15=28.00>>28.00.
Alipata punguzo la 25% kwenye vitabu hivi viwili hivyo 28*.25 = $7.00.
Hivi vitabu viwili vimegharimu 28-7 = $<<28-7=21.00>>21.00.
Ananunua vitabu 4 jumla na hivi viwili vya kwanza vimegharimu $21.00 hivyo 4-2 =2 vitabu vimesalia.
Vitabu vya 3 na 4 vina bei ya $10 kila kimoja hivyo 2*10 = $<<2*10=20.00>>20.00.
Jumla ya vitabu vyote ni 21+20 = $<<21+20=41.00>>41.00.
Ili apate usafirishaji bure anahitaji kutumia 50-41 = $<<50-41=9.00>>9.00 zaidi kwa vitabu.