5-n -3-(-6)
------- = -------- n=?
-1+2n -2-(-5)
如果有既話我想問p.151 Ex.4A ( 3.4.12)
p.131 EX.3C ( 17a,b )
and Workbook p.74-77, 67(5), 62-64, 60(5), 55(b),56,57
幫得幾多得幾多呀...幫一條或耆小小都好呀.....為左分又好,幫下人又好
thx.........