How to use Date.AddDays and Data.AddMonths together

Hi,

I have a date column where I would like to add +1 month and -15 days in Power Query. I can't add +15 days only because we have months with 31 days.

I try to use Date.AddDays([Date], -15), but if possible I would like to use Date.AddMonths in the same function.

Example:

It's possible?

Thanks!