где в программе можно записать решения для функции при разных x? язык VBA

первую функцию вычислить при x=5, а вторую при x=-20. сама программа """

Option Explicit
Public rez As String
Public Sub Zadanie_A(x As Double)
Dim y As Double
If (x <> 1) Then
y = Log(x) / (x - 1)
rez = "Çàäàíèå À: Â x = " & x & " y = " & y
Else
rez = " A: A x = " & x & " "
End If
End Sub
Public Function Zadanie_B(x As Double) As Double
Dim y As Double
Select Case x
Case Is < -1
y = -1
Case Is < 0
y = x
Case Is < 1
y = -x
Case Else
y = -1
End Select
rez = rez & Chr(13) & "A: A  = " & x & " y = " & y
Zadanie_B = y
End Function
Option Explicit
Sub glavnaja()
Zadanie_A 1.2
MsgBox rez
End Sub

"""