
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
Calculate:<br/>$(1)$ Calculate: $2a^{2}+9b-5a^{2}-4b$.<br/>$(2)$ Simplify first, then evaluate: $3mn^{2}+m^{2}n-2(2mn^{2}-m^{2}n)$, where $m=1$, $n=-2$.

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