
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 function $f(x)= \frac {x^{2}}{ax+b}$, where $a$ and $b$ are constants, and the equation $f(x)-x+12=0$ has two real roots $x_{1}=3$ and $x_{2}=4$.

1. Find the analytical expression of the function $f(x)$.
2. Solve the inequality $f(x) < \frac {(k+1)x-k}{2-x}$ for $x$, where $k > 1$.

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