求大神看看哪里错误了

提示除数不能为0
你的代码不全。。。

这是原图

Option Explicit
Dim x As Single, y As Single, c As Single, b As Single, a As Single
Private Sub Command1_Click()
Me.Scale (-10, -10)-(10, 10)
x = -c / b
y = c / a
Me.Line (x, 0)-(0, y), vbBlue
End Sub
Private Sub Text1_Change()
a = Text1
End Sub
Private Sub Text2_Change()
b = Text2
End Sub
Private Sub Text3_Change()
c = Text3
End Sub


我先试试哈