x+y+z=51 4x+8y+5z=300 x+y+2z=67

x+y+z=51 4x+8y+5z=300 x+y+2z=67 (x+y-z)(x-y+z)= (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai x/2=y/3=z/5 x+3y-z/x-3y+z X+Y+Z=? {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 三元一次方程x+y+z=5 4x+8y+5z=300 x+y+2z=67 解方程组{X+Y+Z=51 4X+8Y+5Z=300 X+Y+2Z=61 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, (x+y-z)^2-(x-y+z)^2=? 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X