
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 an arithmetic sequence $\{a_n\}$ that satisfies: $(a_3=7,a_5+a_7=26)$, and the sum of the first $n$ terms of the sequence is denoted as $(S_n)$.

(1) Find $(a_n)$ and $(S_n)$;

(2) Let $\{b_n=\frac{1}{a_n^2-1}(n\in N^{+})\}$, find the sum of the first $n$ terms of the sequence, denoted as $(T_n)$.

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