Can I use PowerApps with Excel files containing formula?
As a short answer, No you can't use Excel files containing formula in PowerApps right now.
If you have tried to use Excel files containing formula in PowerApps, you will get this error:
Excel files containing formula are currently not supported in PowerApps. Therefore, you must use an excel file that has no formula.
Workaround to use excel file containing formula in PowerApps
Actually, there is no workaround to use excel file containing formula in PowerApps right now.
However, there is already an idea that has submitted to PowerApss User Voice.
The idea status is "Under Review", so we do hope it will be accepted and implemented by Microsoft Team soon.
As a workaround, you could convert all required excel formula as a PowerApps formula when you add a new item in PowerApps.