3元一次方程组

来源：百度知道 编辑：UC知道 时间：2024/06/02 16:18:29
X/3=Y/4=Z/5
X-2Y+3Z=30
快啊

X/3=Z/5, X=3Z/5;
Y/4=Z/5, Y=4Z/5;
将以上的X和Y代入X-2Y+3Z=30内：
3Z/5-2(4Z/5)+3Z=30
Z(3/5-8/5+3)=30
Z(3-8+15)/5=30
2Z=30
Z=15

x=3y/4
z=5y/4
x-2y+3z=3y/4-2y+15y/4=30
y=12 x=9 z=15

x=3y/4
z=5y/4
x-2y+3z=3y/4-2y+15y/4=30
y=12 x=9 z=15
X/3=Z/5, X=3Z/5;
Y/4=Z/5, Y=4Z/5;
将以上的X和Y代入X-2Y+3Z=30内：
3Z/5-2(4Z/5)+3Z=30
Z(3/5-8/5+3)=30
Z(3-8+15)/5=30
2Z=30
Z=15