Hide formulas without protecting Sheet

I think the question is why you say 'without protecting the sheet'. My guess is because you need them to be able to enter information in other parts of the sheet so you need to select the regions/cells that you want the users to be able to edit, goto 'Format Cells', select the 'Protection' tab and UNselect 'Locked'. Then when you protect the sheet those cells will not be locked and others can still edit them.