中4數
解:4x+9y=2y+3x+4=5x+7y+5
解4x+9y=2y+3x+4=5x+7y+5
2013-10-29 5:58 am
回答 (1)
2013-10-29 6:05 am
✔ 最佳答案
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4x + 9y = 2y + 3x + 4 = 5x + 7y + 5
拆兩條式做，否則無野做到．．．
{4x + 9y = 2y + 3x + 4
{4x + 9y = 5x + 7y + 5
{x + 7y = 4 ...[1]
{-x + 2y = 5 ...[2]
[1]+[2] 得 9y = 9
y = 1
[1]: x + 7 = 4
x = -3
所以：
{ x = -3
{ y = 1
收錄日期: 2021-04-13 19:46:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131028000051KK00234