
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
Given: $A=x^{2}-3xy-y^{2}$, $B=x^{2}-3xy-3y^{2}$.  
$(1)$ Find the expression $M=2A-B$;  
$(2)$ When $x=-2$, $y=1$, find the value of the expression $M$.

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