
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The taxi fare standard in a certain city is as follows: a fare of 10 yuan for distances within 3 km (including 3 km); for the part exceeding 3 km but not more than 18 km, the fare is 1 yuan per km; for the part exceeding 18 km, the fare is 2 yuan per km.  
(1) If someone travels 20 km by taxi, how much does he need to pay? How much does one need to pay if he travels x km by taxi?  
(2) If someone pays a fare of 22 yuan, how far did he travel by taxi? How far did one travel by taxi if he pays a fare of 10 + x (x > 0) yuan?

Present the answer in LaTex format: \boxed{Your answer}
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