百度 我要提问3x+y+2z=28,5x-3y+z=7,试说明x+y+z=15

百度 我要提问3x+y+2z=28,5x-3y+z=7,试说明x+y+z=15 x/2=y/3=z/5 x+3y-z/x-3y+z 解三元一次方程组.速回.（1）X+Y+Z=25 X-Y=1 2X+Y-Z=18（2）X-Y-Z=0 X+Y-3Z=4 2X+3Y-5Z=14（3） X-2Y=-9 Y-Z=3 2Z+x=47（4）3X-y+z=4 2X+3Y-Z=12 X+Y+z=-28（5）4X+9Y=13 3y-2Z=-1 7X+5Z=17速回 我会奖励积分 x+y+z=2 x-3y+2z=1 2x+2y+z+5 要具体步骤.. 三元一次方程解 1.{x+y-z=5 {3x+2y+z=2 {2x-2y+z=-31.{x+y-z=5 2.{9x-5y+x=-6 3.{x-y=3 4.{x+y=3 5.{4x-2y+z=7{3x+2y+z=2 {9x+y-2z=3 {x+z=7 {y+z=4 {2x-y-3z=28{2x-2y+z=-3 {-9x+3y-5z=0 {y-z=6 {z+x=5 {x+y-2z=13 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. {2x+5y=13z+1000 {3x+3z=9y {6y+8z=5x-6000 要详细过程,帮我解方程{2x+5y=13z+1000{3x+3z=9y{6y+8z=5x-6000要详细过程，帮我解方程 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知实数x,y,z满足x+y=5,z^2=xy+y-9,那么x+2y+3z=?我很着急 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 数学x–y+3z=28 x:y:z=1:2:5 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 帮我解方程组：3x-y+z=3,2x+y-3z=11,x+y+z=12.x=?y=?z=? 已知2x+3y+z=130,3x+5y+z=180,试求x+2y/x+y+z的值 要正确的! x+y=5 2x+3y-z=9 x-y+z=4 解下列三元一次方程组 1. x-4y+z=-3 2x+y-z=18 x-y-z=7 2. x:y:z=2:3:5 x+y+z=100 要过程 谢谢 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值