3y=2x 4y=5z x+y+z=66 这个三元一次方程组怎么解?

来源：学生作业学帮网编辑：学帮网时间：2024/05/05 09:06:25

3y=2x 得y=2/3x
4y=5z 得y=5/4z
两式得2/3x=5/4z得z=8/15x
x+y+z=x+2/3x+8/15x=33/15x=66
解得x=30 y=2/3x=20 z=8/15x=16

3y=2x -----(1)
4y=5z -----(2)
x+y+z=66 -----(3)
由（1）得：y=(2/3)x, 由（2）得：z=(4/5)y=(4/5)(2/3)x=(8/15)x
带入（3）得：
x+(2/3)x+(8/15)x=66
x=30
y=(2/3)x=20
z=(8/15)x=16

3y=2X
则x=3y/2
4y=5z
则有z=4y/5
把以上带入x+y+z
得3y/2+y+4y/5=66
解此方程得y=20
把y=20代入方程3y=2x
得60=2x
则x=30
同理z=16

x=3/2y,z=4/5y,带入x+y+z=66则66/y=1+3/2+4/5=1+1.5+0.8=3.3
y=20.带入第1和2式得x=30,z=16

X=3/2Y Z=4/5y
x+y+z=66
y=66-3/2y-4/5y
y+15/10y+8/10y=66
23/10y=66
y=660/23
y=28.696
x=19.037
z=35.87

x:y=3:2 y:z=5:4 x+y+z=66 x:y=3:2 y:z=5:4 x+y+z=66 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 x+y/2=z+x/3=y+z/4 x+y+z=27 x/2=y/3=z/5 x+3y-z/x-3y+z x+2y=3x+2z=4y+z 求x:y:z (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x+y=5 2x+3y-z=9 x-y+z=4 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. ①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66 (1)2X+4Y+3Z=93X-2Y+5Z=115X-6Y+7Z=13(2)X:Y=3:2Y:Z=5:4X+Y+Z=66(3)3X-Y+Z=32X+Y-3Z=11X+Y+Z=13以上3个题目为三元一次方程~ (x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y z 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. {x:y=2:3 y:z=4:5 x+y+z=35