'фак. №5349
'двоен корен --> 3
'два корена  --> 5, 9

Dim root1 As Double = 5
Dim root2 As Double = 9
Dim x As Double

x = 0

Select Case x
    Case root1
        Console.WriteLine("x is a root of the quadratic equation.")
    Case root2
        Console.WriteLine("x is a root of the quadratic equation.")
    Case Else
        Dim result As Double = (x ^ 2) - ((root1 + root2) * x) + (root1 * root2)
        Console.WriteLine("The result of the quadratic equation for x is: " & result)
End Select