Essentially, you need to break it down into:
1) Revenue uplift synergies (volume increase, price increase, etc....make it situation specific)
2) Cost reduction synergies (reduction in back-office through consolidation, COGS through buyer power, etc.)
3) Ability to realize synergies - costs to implementing, odds of being successful etc.
1) People - who to hire/fire, how to re-organize, etc.
2) Processes - which processes to adopt, which to merge + how, etc.
3) Tools - which tools to implement from each company, which to integrate/merge and how, etc.
That said, this totally depends on the case and prompt itself!