
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 vectors $\overrightarrow{a}=(1,1)$, $\overrightarrow{b}=(2x,x)$, $\overrightarrow{c}=(3,1)$,
(I) If $(\overrightarrow{a}+\overrightarrow{b})$ is parallel to $\overrightarrow{c}$, find the value of the real number $x$;
(II) If the angle between $(\overrightarrow{a}+\overrightarrow{b})$ and $\overrightarrow{c}$ is $45^\circ$, find the value of the real number $x$.

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