Решить СЛАУ методом Гаусса

Option Explicit
    Dim a(3, 4) As Double, i As Integer, j As Integer, k As Single
 
Private Sub Command1_Click()
    a(1, 1) = 1: a(1, 2) = 3: a(1, 3) = -1: a(1, 4) = 4
    a(2, 1) = -1: a(2, 2) = 2: a(2, 3) = 3: a(2, 4) = 12
    a(3, 1) = 2: a(3, 2) = 1: a(3, 3) = -1: a(3, 4) = 1
    
    myPrint
    
    k = (a(3, 1) / a(1, 1))
    For i = 1 To 4
        a(3, i) = a(3, i) - k * a(1, i)
    Next
    k = (a(2, 1) / a(1, 1))
    For i = 1 To 4
        a(2, i) = a(2, i) - k * a(1, i)
    Next
    k = (a(3, 2) / a(2, 2))
    For i = 1 To 4
        a(3, i) = a(3, i) - k * a(2, i)
    Next
    a(3, 4) = a(3, 4) / a(3, 3)
    a(3, 3) = 1
    
    a(2, 4) = a(2, 4) - a(3, 4) * a(2, 3)
    a(2, 3) = 0
    a(2, 4) = a(2, 4) / a(2, 2)
    a(2, 2) = 1
    
    a(1, 4) = a(1, 4) - a(3, 4) * a(1, 3) - a(2, 4) * a(1, 2)
    a(1, 2) = 0
    a(1, 3) = 0
    a(1, 4) = a(1, 4) / a(1, 1)
    a(1, 1) = 1
    
    myPrint
    
End Sub
 
Sub myPrint()
    Print CStr(a(1, 1)) + vbTab + CStr(a(1, 2)) + vbTab + CStr(a(1, 3)) + vbTab + CStr(a(1, 4))
    Print CStr(a(2, 1)) + vbTab + CStr(a(2, 2)) + vbTab + CStr(a(2, 3)) + vbTab + CStr(a(2, 4))
    Print CStr(a(3, 1)) + vbTab + CStr(a(3, 2)) + vbTab + CStr(a(3, 3)) + vbTab + CStr(a(3, 4))
    Print vbCrLf
End Sub