Option Explicit
Sub reduire_lignes()
Dim i As Integer, dl As Integer
With Sheets("exemple")
dl = .Cells(Rows.Count, 1).End(xlUp).Row
For i = dl To 1 Step -1
If .Cells(i, 1).Value = .Cells(i, 1).Offset(1, 0).Value Then
.Cells(i, 6).Value = .Cells(i, 6).Value + .Cells(i, 6).Offset(1, 0).Value
.Cells(i, 7).Value = .Cells(i, 7).Value & "/" & .Cells(i, 7).Offset(1, 0).Value
.Cells(i, 1).Offset(1, 0).EntireRow.Delete
End If
Next i
End With
End Sub