Imports System

Public Module Module1

    Sub Main()

        Dim a, b, x as Single

        Console.Writeline("cb a ?")

        a = Console.Readline()

        Console.Writeline("cb b ?")

        b = Console.Readline()

        If a=0 Then Console.Writeline("impossible ?")

        Else x=-b/a Console.Writeline("x=" & x)

        End If  

    End Sub

End Module