x+y/3+x-y/2=6 4(x+y)-2(x-y)=40

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/15 17:17:57
x+y/3+x-y/2=6 4(x+y)-2(x-y)=40
xRN@.N¢ÿiS†bD *0QyD6EՏ>`/8bj眜{OR˒›bYBDpYeh#KpN;H/jٓ)#nd׳U߻ 1JQSMz=f8f$ 3O&p"E+"#¹[-F)]HK:,h0o߁k}_وB0O۠(Y,"*X $D6)1=oA5Gԅ`}1)Y%Jzۍf8zNQjӰ>-jm)

x+y/3+x-y/2=6 4(x+y)-2(x-y)=40
x+y/3+x-y/2=6 4(x+y)-2(x-y)=40

x+y/3+x-y/2=6 4(x+y)-2(x-y)=40
答:
(x+y)/3+(x-y)/2=6
4(x+y)-2(x-y)=40
整理得:
2(x+y)+3(x-y)=36
2(x+y)-(x-y)=20
两式相减得:
4(x-y)=16
x-y=4
代入得:2(x+y)-4=20
x+y=12
结合x-y=4解得:
x=8,y=4

(x+y)/3+(x-y)/2=6,①
4(x+y)-2(x-y)=40,②
①*4+②,(16/3)(x+y)=64,x+y=12,③
①*12-②,14(x-y)=32,x-y=16/7.④
(③+④)/2,x=50/7,
(③-④)/2,y=34/7.
∴{x=50/7,
{y=34/7.
希望能解决您的问题。

令x+y=u, x-y=v
所以原方程变为
2u+3v=36
4u-2v=40
解得
u=12
v=4
所以x+y=12
x-y=4
解得x=8, y=4

x,y=8或4