初二数学解二元一次方程组要过程{4X+3Y=1{7X-6Y=32{M/2+N/3=2{0.2M+0.3N=2.8

[1]4X+3Y=1 (1)
7X-6Y=32 (2)
(1)×2+(2)
8X+6Y+7X-6Y=2+32
15X=34
X=34/15
Y=(7X-32)/6=-121/45

M/2+N/3=2 (1)
0.2M+0.3N=2.8 (2)
(1)×2-(2)×5
M+2N/3-M-1.5N=4-14
-5N/6=-10
N=12
M=2(2-N/3)=4 [2] 上面同时乘以2，
8X+6X=2........1
7X-6X=32........2
1+2
15X=34
X=34/15
Y=29/20
上面同时乘以6，下面同时乘以15
3M+2N=12..........1
3M+4.5N=42.........2
2-1
2.5N=30
N=8
M=-6

上面同时乘以2，
8X+6X=2........1
7X-6X=32........2
1+2
15X=34
X=34/15
Y=29/20
上面同时乘以6，下面同时乘以15
3M+2N=12..........1
3M+4.5N=42.........2
2-1
2.5N=30
N=8
M=-6

4X+3Y=1 (1)
7X-6Y=32 (2)
(1)×2+(2)
8X+6Y+7X-6Y=2+32
15X=34
X=34/15
Y=(7X-32)/6=-121/45

M/2+N/3=2 (1)
0.2M+0.3N=2.8 (2)
(1)×2-(2)×5
M+2N/3-M-1.5N=4-14
-5N/6=-10
N=12
M=2(2-N/3)=-4