
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: $A=2a^{2}-5ab+3b$, $B=4a^{2}+6ab+8a$.  
$(1)$ Simplify: $2A-B$;  
$(2)$ If $a=-1$, $b=2$, find the value of $2A-B$;  
$(3)$ If the value of the algebraic expression $2A-B$ is independent of $a$, find the value of $b$.

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