3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9

来源:学生作业帮助网 编辑:六六作业网 时间:2024/05/15 07:19:08
3(x+y)-2(x-y)=114(x+y)+3(x-y)=93(x+y)-2(x-y)=114(x+y)+3(x-y)=93(x+y)-2(x-y)=114(x+y)+3(x-y)=93(x+y)-

3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9
3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9

3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9
3(x+y)-2(x-y)=11
4(x+y)+3(x-y)=9
令x+y=a,x-y=b,则原方程组变成:
3a-2b=11
4a+3b=9
解得:a=3,b=-1

x+y=3
x-y=-1
解得:x=1,y=2

x+5y=11;
7x+y=9;
x=1;y=2