Sub Verif_declar()
Dim Derligne As Long, Dercol As Long
Derligne = Sheets("Feuil1").Range("A" & Application.Rows.Count).End(xlUp).Row
Dercol = ActiveSheet.UsedRange.SpecialCells(xlCellTypeLastCell).Column
Range(Cells(2, Dercol + 1), Cells(Derligne, Dercol + 1)).FormulaLocal = "=A2-B2"
End Sub