聯立2元1次問題
4x+5y=1......(1)
2x-y+3=0......(2)
x=-1
y=1
d步驟係點寫呀
我計泥計去都計唔到呀
唔該幫幫手教我計呀
我想用代入既方法 唔係(2)-(1)個d
同埋我想由(1)得出(3)
再將(3)代入(2)
應該點寫呀
聯立2元1次方程的問題
2007-09-21 12:08 am
回答 (1)
2007-09-21 12:18 am
✔ 最佳答案
4x+5y = 1....(1)2x-y+3 = 0....(2)
in(2) 2x-y+3 = 0
-y = -2x-3
y = 2x+3...(3)
sub(3) into (1)
4x+5(2x+3) = 1
4x+10x+15 = 1
14x = -14
x = -1
since x = -1, in (2) 2x-y+3 = 0
2(-1)-y+3 = 0
-2-y+3 = 0
1-y = 0
y = 1
x=-1 and y =1
參考: My Maths Knowledge
收錄日期: 2021-05-03 06:05:56
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070920000051KK01643