
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
For some nonzero numbers \(a, b, c,\) and \(d\), the following equality holds: \(\frac{a}{b} + \frac{c}{d} = \frac{a+c}{b+d}\). Determine the sign of the number \(ac\).

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