Option Explicit

Sub test()
    Dim Cell As Range
    Dim ws As Worksheet
    For Each ws In Worksheets(Array("130R", "135R", "140R"))
        For Each Cell In ws.Range("E4:P45")
            If Cell.Value > 0 Then
                Cell.Value = Cell.Value * -1
            End If
        Next Cell
    Next ws
End Sub