line(i,0)=(xy(i,1)-xy(i+1,1))/(xy(i,0)-xy(i+1,0))
这条语句系统提示我缺少“-”号 为什么？

Dim xy(4, 2), i, j, line(4, 2)
Dim xyc As Variant
xyc = Array(225.1918, 234.7751)
For i = 0 To 1
xy(0, i) = xyc(i)
Next
xyc = Array(133.3644, 347.3243)
For i = 0 To 1
xy(1, i) = xyc(i)
Next
xyc = Array(126.949, 183.9804)
For i = 0 To 1
xy(2, i) = xyc(i)
Next
xyc = Array(225.1918, 70.6234)
For i = 0 To 1
xy(3, i) = xyc(i)
Next
For i = 0 To UBound(xy) - 2
line(i,0)=(xy(i,1)-xy(i+1,1))/(xy(i,0)-xy(i+1,0))
line(i,1)=(xy(i,0)*xy(i+1,1)-xy(i+1,0)*xy(i,1))/(xy(i,0)-xy(i+1,0))
Next i
我想求两点的莲线表达式

哦 小弟时初学者 汗