
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
$(1)\left(2m+n\right)^{2}-\left(4m+3n\right)\left(m-n\right)$;  
$(2)[\frac{(2x+1)(3x-4)}{2{x}^{2}-5x-3}-1]÷\frac{4{x}^{2}-1}{x-3}$.

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