
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 two lines $l_1: y = 2x$, $l_2: y = -2x$, and a line $l$ passing through point $M(-2, 0)$ intersects $l_1$ and $l_2$ at points $A$ and $B$, respectively, where point $A$ is in the third quadrant, point $B$ is in the second quadrant, and point $N(1, 0)$;  
(1) If the area of $\triangle NAB$ is 16, find the equation of line $l$;  
(2) Line $AN$ intersects $l_2$ at point $P$, and line $BN$ intersects $l_1$ at point $Q$. If the slopes of line $l$ and $PQ$ both exist, denoted as $k_1$ and $k_2$ respectively, determine whether $\frac {k_{1}}{k_{2}}$ is a constant value? If it is a constant value, find this value; if not, explain why.

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