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

### Instruction:
 一台木炉早上烧了4捆木柴，然后下午又烧了一些。如果一天开始时有10捆木柴，一天结束时有3捆木柴，那么下午烧了多少捆木柴？


### Response:
 设x为下午烧掉的木柴数量。
早上烧掉的木柴数量为4捆 + x捆 = 10捆
2x捆 = 10捆 - 4捆
2x = 6捆
x = <<3=3>>3捆