maths~~~
2010-04-22 9:44 pm
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回答 (2)
2010-04-22 10:12 pm
✔ 最佳答案
Sol
設 z=ax+by
5=a*1+b*1，3=a*1+b* 2
a+b=5，a+2b=3
b=－2，a=7
z=7x－2y
題目改為另一部份隨y反變
z=ax+b/y
5=a*1+b/1，3=a*1+b/ 2
a+b=5，2a+b= 6
a=1，b=4
z=x+4/y
選(C)
2010-04-22 10:02 pm
subsititute x=1, y=1
only A and C gives the z value as 5
set x=1, y=2 for A and C
C gives z=3
So C is the answer
only A and C gives the z value as 5
set x=1, y=2 for A and C
C gives z=3
So C is the answer
收錄日期: 2021-04-23 20:41:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100422000051KK00430