解二元一次方程组x⼀2+y⼀3=9 x-y=12 急求啊

2024-12-23 05:36:41
推荐回答(4个)
回答1:

x/2 + y/3 = 9
x - y = 12

3x/2 + y = 27
x - y = 12

5x/2 = 39

x = 15.6
y = 3.6

回答2:

x/2+y/3=9 (1)
x-y=12 (2)

(1)*6得
3x+2y=54 (3)
(2)*2+(3)得
5x=78
x=78/5
将x=78/5代入(2)得
78/5-y=12
y=18/5

回答3:

x/2+y/3=9 x-y=12
3x+2y=54
2x-2y=24
5x=78
x=78/5
y=18/5
他们是对的

回答4:

x/2+y/3=9 x-y=12

3x+2y=54
2x-2y=24

5x=78
x=78/5
y=18/5