You can do either, it's up to you:
Dim v1 As Integer
Dim v2 As Integer
Dim isConverted1 As Boolean = Integer.TryParse(s1, v1)
Dim isConverted2 As Boolean = Integer.TryParse(s2, v2)
Or
Dim v1 As Integer
Dim v2 As Integer
Dim isConverted As Boolean = Integer.TryParse(s1, v1) AndAlso Integer.TryParse(s2, v2)