2x=3y 2y=3z x+y+2z=400 只能是正数求出X，Z

分类: 作业答案 • 2022-04-12 12:39:31

问题描述：

2x=3y 2y=3z x+y+2z=400 只能是正数
求出X，Z

答

两边乘以6
6X+6Y+12Z=2400
3*2X+6Y+4*3Z=2400
9Y+6Y+8Y=2400
Y=2400/23
X=3/2*Y=7200/46
Z=2/3*Y=1600/23

答

X=3Y/2
Z=2Y/3
3Y/2+Y+2Y/3=400
Y=2400/19
X=3600/19
Z=1600/19

答

x=3y/2
x=2y/3
3y/2+y+4y/3=400
9y+6y+8y=2400
23y=2400
y=2400/23
x=3600/23
x=1600/23

答

x=3/2y
z=2/3y
3/2y+y+4/3y=400
所以 y=2400/23
x=3/2y=3600/23
z=2/3y=1600/23