(X+5)/(Y+5)=Z+150.(X+5厘米/(Y+5厘米)=（Z+150）平方厘米

x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 x/2=y/3=z/5 x+3y-z/x-3y+z x+y+z=15 x+5y+10z=70 x,y,z,各是几? x+y+z=15 x+5y+10z=70 x,y,z,各是几? X+Y-Z=15 X+5Y+10Z=70 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=4x-5y=y-x+6z,xyz不等0,x:y:z=? (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? X+Y+Z=15 X+5Y+10Z=70,Y.Z的值 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=5 2x+3y-z=9 x-y+z=4 {x+y+z=12 x+2y+5z=22 x=4y 6x+5y+3z=100 x+y+z=30 求 x y 已知3X=4X,5Y=6Z求X+Y：Y+Z 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值