p. 214
42.
-x + 2y 3x + 6y
____________ + _____________
4y + 2x 2x - 4y
43.
3x 6y
______ ^ ________
x -2 2x - 4y
51.
p +t
a = ------------
s - t
52.
ab + c (b +1) =a
收錄日期: 2021-04-23 20:35:33
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081218000051KK01202