
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) Simplify $$\frac {sin(-x)cos(π-x)}{sin(π +x)cos(2π -x)}$$ - $$\frac {sin(π-x)cos(π+x)}{cos( \frac {π}{2}-x)cos(-x)}$$
(2) Given vectors $$\overrightarrow {OA}$$ = (k, 12), $$\overrightarrow {OB}$$ = (4, 5), and $$\overrightarrow {OC}$$ = (10, k), determine the value of k for which points A, B, and C are collinear.

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