怎样在vb上 画一个二元一次方程的图 求编码

Private Sub Command1_Click()
zhixian 1,2,3
End Sub
Sub zhixian(A As Single,B As Single,C As Single)
'Ax+By+C=0
Dim x1 As Single,y1 As Single
Dim x2 As Single,y2 As Single
x0 = 1000
y0 = 1000
x1 = -500
y1 = (-C - A * x1) / B
x1 = x1 + x0
y1 = y1 + y0
x2 = 500
y2 = (-C - A * x2) / B
x2 = x2 + x0
y2 = y2 + y0
Line (0,1000)-(2000,1000)
Line (1000,0)-(1000,2000)
Line (x1,y1)-(x2,y2)
End Su