Business & farm

So I purchased a printer for my ebay business....I have the receipt, but I purchased it along with groceries and other items.  The printer is about $100.  Is that receipt valid even though it includes other non-business items.   I obviously cant deduct eggs and ground beef that are on the receipt, so I assume I just itemize or highlight?

 

Do i need to attach all receipts to my return? Or just keep them in my records?