
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 that the sum of the polynomials $A$ and $B$ is $12x^{2}y+2xy+5$, where $B=3x^{2}y-5xy+x+7$. Find:<br/>$(1)$ The polynomial $A$;<br/>$(2)$ When $x$ takes any value, the value of the expression $2A-\left(A+3B\right)$ is a constant. Find the value of $y$.

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