2x+y=10① 4y+z=21② 5x-z=10③ y,z各为多少?

(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x-y-2z=10 y-3z=-4 3x-y+5Z=21 三元一次方求大神x-y-2z=10y-3z=-43x-y+5Z=21 2x+y=10① 4y+z=21② 5x-z=10③ y,z各为多少? ①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66 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 ①5x-4y+4z=132x+7y-3z=193x+2y-z=18②y=2x-75x+3y+2z=23x-4z=4 {x+y-2z=5① {2x-y+z=4② {2x+y-3z=10③ 解一元三次方程 要过程 三元一次方程求解：①x+2z=3,2x+y=2,2y+z=7.②x+y+z=2,3x-y-4z=5,2x+3y-2z=0. 解方程组x+y/2=z+x/3=y+z/4①x+y+z=27② X-Y-Z=0 X+Y-3Z=4 2X-5Y+7Z=21 -2X+3Y+Z=-4-X-5Y-2Z=-13X+Y-Z=10 x+y+2z=5 2x-y-z=4 3x+y-3z=10 {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 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 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 ①X+Y+Z=111②Y:X=3:2③Y:Z=5:4求x,y,z急～