
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/>Given $A=b^{2}-a^{2}+5ab$, $B=3ab+2b^{2}-a^{2}$.<br/>$(1)$ Simplify: $2A-B$;<br/>$(2)$ When $a=1$, $b=2$, find the value of $2A-B$.

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