
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
In the Cartesian coordinate system $xOy$, there is a line $l: 2x+y-4=0$.

(1) If line $m$ passes through point $A(2,1)$ and is perpendicular to line $l$, find the equation of line $m$;

(2) If line $n$ is parallel to line $l$ and the sum of the intercepts on the $x$-axis and $y$-axis is 9, find the equation of line $n$.

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