6x-y=2
3x+2y=2
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2010-08-12 12:56 am
回答 (4)
2010-08-12 1:08 am
✔ 最佳答案
6x - y = 2 ... (1)3x + 2y = 2 ... (2)
從(1), y = 6x - 2 ... (3)
代(3)入(2),
3x + 2(6x - 2) = 2
3x + 12x - 4 = 2
15x = 6
x = 2/5
代 x = 2/5 入 (3),
y = 6(2/5) - 2 = 2/5
所以 x = 2/5 , y = 2/5 .
2010-08-11 17:10:39 補充：
這兩條方程不是一樣的.
參考: ME, ME
2010-08-12 3:03 am
6x-y=2 --- ( 1 )
3x+2y=2 --- ( 2 )
( 1 ) - ( 2 )
6x - 3x - y - 2y = 2 - 2
3x - 3y = 0
x - y = 0
x = y --- ( 3 )
sub ( 3 ) into ( 1 )
6x - x = 2
5x = 2
x = 0.4 --- ( 4 )
sub ( 4 ) into ( 3 )
y = 0.4
So , x = 0.4 and y 0.4 .
3x+2y=2 --- ( 2 )
( 1 ) - ( 2 )
6x - 3x - y - 2y = 2 - 2
3x - 3y = 0
x - y = 0
x = y --- ( 3 )
sub ( 3 ) into ( 1 )
6x - x = 2
5x = 2
x = 0.4 --- ( 4 )
sub ( 4 ) into ( 3 )
y = 0.4
So , x = 0.4 and y 0.4 .
2010-08-12 1:24 am
2010-08-12 1:05 am
6x-y=2 ----1
3x+2y=2 ----2
從1, 6x-y=2
y=6x-2 ----3
將3代入2, 3x+2y=2
3x+2(6x-2)=2
3x+12x-4=2
15x=6
x=0.4
將x=0.4代入3, y=6x-2
y=6(0.4)-2
y=0.4
所以 x=0.4 , y=0.4
3x+2y=2 ----2
從1, 6x-y=2
y=6x-2 ----3
將3代入2, 3x+2y=2
3x+2(6x-2)=2
3x+12x-4=2
15x=6
x=0.4
將x=0.4代入3, y=6x-2
y=6(0.4)-2
y=0.4
所以 x=0.4 , y=0.4
收錄日期: 2021-04-15 17:30:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100811000051KK01212