已知量：T1,RI,K
      可变量：T2,R2
公式及限制值：(R2-R1)*(D+T1)/R2+T2-T1<=80

dim i as long

i= (R2-R1)*(D+T1)/R2+T2-T1
if i<=80 then
   msgbox "小于等于80"
else
   msgbox "大于80"
end if

运行时，显示：实时错误'6':
              溢出

你数据超范围了.
那你声明:

dim i as Double

吧.如果还溢出,那就真正无语了.

还是溢出啊！

你一句代码也没有，谁知道你是怎么算的啊

给变量赋值！

Private Sub Command1_Click()
       Dim T1 As Integer, R1 As Integer, D As Integer      
        Dim T2 As Integer, R2 As Double
           For T2 = 0 To 10
            For R2 = 0 To 10            
                 F = (R2 - R1) * (D + T1) / R1 + T2 - T1
                   If F <=80 Then
                       Text1.Text = Text1.Text & T2 & "," & R2 &  vbCrLf
                End If
            Next R2            
        Next T2
End Sub

运行起来还有些错误

F = (R2 - R1) * (D + T1) / R1 + T2 - T1'这里R1还没有赋值，默认为0，当然会出错哦

修正后的代码：

Private Sub Command1_Click()

       Dim T1 As Integer, R1 As Integer, D As Integer
        Dim T2 As Integer, R2 As Double
          T1 = 20
          R1 = 30
          D = 225
        
           For T2 = 0 To 10
            For R2 = 0 To 10
                 F = (R2 - R1) * (D + T1) / R1 + T2 - T1
                   If F <= 80 Then
                       Text1.Text = Text1.Text & T2 & "," & R2 & vbCrLf
                End If
            Next R2
        Next T2

End Sub



终于能正常运行，多谢各位的支持！