Using VBA, try it like this, for a used range on a sheet.
Worksheets(Array("Sheet1", "Sheet2")).Select
ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
"C:\Consolidated.pdf", Quality:= xlQualityStandard, IncludeDocProperties:=True, _
IgnorePrintAreas:=False, OpenAfterPublish:=True
Or, if you want specific ranges, do it like this.
one = Worksheets("Sheet1").Range("A1:B10")
two = Worksheets("Sheet2").Range("A1:B10")
three = Worksheets("Sheet3").Range("A1:B10")
Worksheets(Array(one, two, three)).Select
ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
"C:\Consolidated.pdf", Quality:= xlQualityStandard, IncludeDocProperties:=True, _
IgnorePrintAreas:=False, OpenAfterPublish:=True
one = ""
two = ""
three = ""