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

### Instruction:
 加布里埃尔比弗兰克小3岁。他们两个人的年龄总和现在是17岁。弗兰克多大了？


### Response:
 设X为弗兰克的年龄。
所以加布里埃尔的年龄是X-3岁。
他们两个人的年龄总和是X + (X-3) = 17岁。
2X-3 = 17
2X = 20
X = 10
所以弗兰克的年龄是X = <<10=10>>10岁。