x+y+z=20 8x+6y+5z=120这个方程组有几个答案?

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 解方程 x(x+y+z)=6 y(x+y+z)=12 z(x+y+z)=18 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 x+y=8 y+z=12 x+z=10 x+y+z= x+y=8 y+z=12 x+z=10 x+y+z= 帮忙解这几道三元一次方程组(1)X-Y+Z=22X-3Y-Z=-7Z=3(2)X+Y+Z=6X-2Z=12X-2Y+Z=3(3)X+Y=8Y+Z=6Z+X=4(4)X-Y=3Y-Z=4X+Z=5(5)2X+3Y-Z=102X+Y-5Z=8-2X+7Y+Z=20(6)2X+Y+Z=3X+2Y+Z=4X+Y+2Z=5(7)X:Y=2:1X+Y+Z=23X+2Y-2Z=10第一天上课没听懂明天上课绝 已知x+y+z=12,x+2*y+2*z=20,求5*x+6*y+8*z的最大值?如题 (x+y-z)(x-y+z)= ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-6=0③x/3=y/2 y/4=z/5 x+y+z=60三元一次方程 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. x/3=y/6=z/8 3x+5y-6z=-18 求x,y,z 三元一次方程组,1.x-2y+z=9 2x+y+3z=10 3x+2y1.x-2y+z=92x+y+3z=103x+2y-z2.3x-5y+2z=14x+5y-z=5X-5y+3z=-23.7x+2y-z=76x-y+z=74x+3y+z=94.4x+3y-2z=-75x-6y+z=12x+z=-25.2x+3y-4z=-23x-2y+5z=262x+5z=31 方程组 ｛5x+8y+12z=100 x+y+z=14 方程组｛5x+8y+12z=100x+y+z=14 已知x:y=3:6,y:z=8:5求x:y:z 三元一次方程组2x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=262x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=26 x+y+z=4x-5y=y-x+6z,xyz不等0,x:y:z=? 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=?