解方程组{0.2x+0.3y=-0.1,0.5x+(y⼀3)=1

2024-12-25 11:15:48
推荐回答(4个)
回答1:

0.2x+0.3y=-0.1
2x+3y=-1

0.5x+(y/3)=1
4.5x+3y=9
两式相减
4.5x-2x=9+1
2.5x=10
x=4

2x4+3y=-1
3y=8+1
3y=9
y=3

回答2:

0.2x+0.3y=-0.1
0.5x+y/3=1
化减
0.5x+0.75y=-0.25
0.5x+y/3=1
相减
3y/4-y/3=-5/4
5y/12=-5/4
y=-3
x=4

回答3:

0.2x+0.3y=-0.1
0.5x+(y/3)=1
x+3y/2=-0.5
x+2y/3=2
5/6y=-2.5
y=-3
x=-0.5-3*(-3)/2=4

回答4:

x=4,y=-3