
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 the universal set $R$, let $A={x|x^2-3x-4\leqslant 0}$ and $B={x|\frac{x-(a+5)}{x-a} > 0}$.

(1) Find $A\cap B$ when $a=-2$;

(2) Find the range of real number $a$ values such that $A\subseteq B$.

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