
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
$(1)$ If the solution set of the inequality $\frac{2x+1}{3-x}＜2$ is $A$, find $\complement _{R}A=\_\_\_\_\_.$<br/>$(2)$ Let $a\in R$, solve the inequality with respect to $x$: $ax^{2}-\left(a+4\right)x+4\leqslant 0$.

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