X+Y+Z=100 0.5X+3Y+5Z =100这个方程咋解 X+Y+Z=100 0.5X+3Y+5Z =100这个方程咋解

x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 0.5x+3y+5z=100 x+y+z=100 x/2=y/3=z/5 x+3y-z/x-3y+z 6x+5y+3z=100 x+y+z=30 求 x y 5x+1.5y+0.5z=100 x+y+z=100 求 X Y Z 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. (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 (x+y-z)(x-y+z)= 请高手帮我解几道3元1次的方程组!好的100分,x+2y+3z=15x-y+7z=20x+3y+2z=14x+y-z=3y+z-x=5z+x-y=7x+y-z=0.5x-3y+2z=03x+2y-z=23x-2y=12y+3z=2x+5z=315x-3y+2z=13x+4y-z=-18z=136x-y-z=32x-4y+8z=53x-6y-z=10x+y=3y+z=5x+z=6 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-2z-(x-2y)]-x-(3y-10z)}=? {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x+2y+3z=23 y-z=5 x+2z=10 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 解方程组：X+Y+Z=100,10X+5Y+0.5Z=100 已知x/y+z=y/x+z=z/x+y,分式(x+2y+3z)/(2x+5y-2c)有意义时的值 x+y+z=35 2x-y=5 y/3=z/2 求x,y,z