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

### Instruction:
A jar contains 9 blue pens, 21 black pens, and 6 red pens. Four blue pens are removed and then seven black pens are removed. How many pens are left in the jar?

### Response:
 Kuna kalamu 9-4 = <<9-4=5>>5 za bluu zilizobaki katika kopo.
Kuna kalamu 21-7 = <<21-7=14>>14 za nyeusi zilizobaki katika kopo.
Kuna jumla ya kalamu 5+14+6 = <<5+14+6=25>>25 zilizobaki katika kopo.