用代入消元法解下列聯立方程..
1) y= x- 1 ,,---(1)
4x+7y=4 ,,---(2)
2)x=3y,,---(1)
2y-3x=28,,---(2)
有冇人可以教下我點計????
更新1:
尼多條= ='' 3) Y=4X+7,,---(1) 4X+Y=7,,---(2) 唔該晒''!!
代入消元法
2007-03-19 5:56 am
代入消元法
用代入消元法解下列聯立方程..
1) y= x- 1 ,,---(1)
4x+7y=4 ,,---(2)
2)x=3y,,---(1)
2y-3x=28,,---(2)
有冇人可以教下我點計????
用代入消元法解下列聯立方程..
1) y= x- 1 ,,---(1)
4x+7y=4 ,,---(2)
2)x=3y,,---(1)
2y-3x=28,,---(2)
有冇人可以教下我點計????
回答 (1)
2007-03-19 6:08 am
✔ 最佳答案
As y = x - 1Put ( 1 ) into ( 2 ) : 4x + 7( x - 1 ) = 4
4x + 7x - 7 = 4
11x = 11 ==> x = 1
Then, put x = 1 into ( 1 ) : y = 1 - 1 = 0
Similarily, you can do like this for Q2
Put ( 1 ) into ( 2 ) : 2y - 3(3y) = 28
-7 y = 28 ===> y = -4
Put y = -4 into ( 1 ) : x = 3 ( -4 ) = -12
收錄日期: 2021-04-23 16:44:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070318000051KK05403