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

### Instruction:
 安娜有曼迪的三倍玩具，比阿曼达少两个玩具。如果他们总共有142个玩具，曼迪有多少个玩具？


### Response:
 设曼迪有x个玩具。
安娜有3*x个玩具。
阿曼达有3*x+2个玩具。
x+3*x+3*x+2=142
7*x+2=142
7*x=140
x=<<20=20>>20