
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
First simplify, then evaluate.
1. Simplify: $-a^2b + (3ab^2 - a^2b) - 2(2ab^2 - a^2b)$;
2. When $(b-1)^2 + |a+3| = 0$, find the value of the above expression.

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