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

### Instruction:
 巴贝克有史蒂夫的两倍吉他，但戴维有巴贝克的三倍吉他。如果总共有27把吉他，戴维有多少把吉他？


### Response:
 设史蒂夫有x把吉他。巴贝克有2x把吉他，戴维有3 * 2x = 6x把吉他。
2x + 6x + x = 27
9x = 27
x = 27 / 9 = <<27/9=3>>3，所以史蒂夫有3把吉他
巴贝克有2 * 3 = <<2*3=6>>6把吉他。
戴维有3 * 6 = <<3*6=18>>18把吉他。