With Sheets("Bx")
For Each cel In .Range("A2:A" & .[A65000].End(xlUp).Row).SpecialCells(xlCellTypeConstants, 23)
cel.Offset(, 11).FormulaR1C1 = IIf(Left(cel, 1) = "T", "=RC[-2]+RC[-1]", "")
cel.Offset(, 12).FormulaR1C1 = IIf(Left(cel, 1) = "T", "=RC[-2]*RC[-1]", "")
Next cel
End With