3x+2y-4z=9,(1) 3x+5y-5z=14(2) 3x-4y+2z=3(3)3x+2y-4z=9,(1)3x+5y-5z=14(2)3x-4y+2z=3(3)适合用( 可用(2)-( ),(3)-( ),得到一个含y,z的二元一次方程组.

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3x+2y-4z=9,(1)3x+5y-5z=14(2)3x-4y+2z=3(3)3x+2y-4z=9,(1)3x+5y-5z=14(2)3x-4y+2z=3(3)适合用(可用(2)-(),(3)-(

3x+2y-4z=9,(1) 3x+5y-5z=14(2) 3x-4y+2z=3(3)3x+2y-4z=9,(1)3x+5y-5z=14(2)3x-4y+2z=3(3)适合用( 可用(2)-( ),(3)-( ),得到一个含y,z的二元一次方程组.
3x+2y-4z=9,(1) 3x+5y-5z=14(2) 3x-4y+2z=3(3)
3x+2y-4z=9,(1)
3x+5y-5z=14(2)
3x-4y+2z=3(3)
适合用( 可用(2)-( ),(3)-( ),得到一个含y,z的二元一次方程组.

3x+2y-4z=9,(1) 3x+5y-5z=14(2) 3x-4y+2z=3(3)3x+2y-4z=9,(1)3x+5y-5z=14(2)3x-4y+2z=3(3)适合用( 可用(2)-( ),(3)-( ),得到一个含y,z的二元一次方程组.
3x+2y-4z=9,(1)
3x+5y-5z=14 (2)
3x-4y+2z=3 (3)
解(2)-(1)得:3y -z = 5 (4)
(2) - (3) 得 :9y -7z = 11 (5)
(4)×3 -(5)得:4z = 4 解得:z = 7
把z=7代入(4)得 3y = 5 + z,y = (5+z)/3 = (5+7)/3 = 4
把 y = 4,z = 7 代入(1)得 3x = 9 - 2y + 4z
x = (9-2y+4z)/3 = (9 - 2×4 + 4×7)/3 = 29/3
所以三元一次方程组的解是:x = 29/3,y = 4,z = 7

已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z. x+y=5 2x+3y-z=9 x-y+z=4 ..1.x+y+z=26,2.4y+3z=7,y-z=1,3x+2z=17,x+2y-z=18 9x-7y=173.x-7y+3z=17 4.2x+4y+3z=95x-6y-z=24 3x-2y+5z=113x+7y-2z=1 5x-6y+7z=131.x+y+z=26,y-z=1x+2y-z=18 2.4y+3z=7,3x+2z=11,9x-7y=17 3.x-7y+3z=17 5x-6y-z=24 3x+7y-2z=14.2x+4y+3z=93x-2y+5z=11 5x-6y+7z=13 (1)x:y:z=3:2:5,2x+3y+8=5 (2)5x-3y+z=5,4x+3y-2z=9x-5y-z=-17 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 已知3x=4Y,5Y=6Z,求 (1)x:y:z;(2)x+y/y+z.请说明道理, 问5道3元一次方程组题目(1) y=2x-7{ 5x+3y+2z=23x-4z=4 (2) 4x+9y=12{3y-2z=17x+5z=19/4(3)4x-9z=17{3x+y+5z=18x+2y+3z=2(4) 2x+4y+3z=9{3x-2y+5z=115x-6y+7z=13(5) x:y=3:2{y:z=5:4x+y+z=66 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 解下列方程组 (1)x=5 x+5-2z=-4 4x-3y+2z=1(2)9x-5y+z=-6 9x+y+4z=3 -9x+3y-5z(3)x+y=22 x+z=-27 y+z=13 三(四)元一次方程组!1.2z-6=-2(x+3y)3(5y+x)=6-7z4(x+z)=9+9y2.2x-5y=-117y+4z=55x+2z=23.0.4x+0.3y-0.2z=40.6x-0.5y+0.3z=50.3x+0.2y+0.5z=224.x/2+3y/4+5z/3=455.1x+6y/5-4z=150.1x-0.4y+4z/5=55.x+y=7y-z=1z+2u=4u-3x=-11 六年级三元一次方程组.解下列方程组:(1)5x-3y+z=25x+2y-4z=3-5x+y-z=2(2)x-y-z=-13x_5y+7z=114x-y+2z=-1(3)9x-5y+z=-69x+y+4z=3-9x+3y-5z=0(4)x+y=22x+z=-27y+z=13 3x+2y+z=9 x-3y-2z=1 -x+4y=5 解三元一次方程组!请写具体的过程!(1)2x+3y=10 (2)x:y=3:2 (3)4x-9z=17 (4)0.4x+0.3y-0.2z=45z+2z=6 y:z=5:4 3x+y+15z=18 0.6x-0.5y+0.3z=53y+5z=4 x+y+z=66 x+2y+3z=2 0.3x+0.2y+0.5z=22第一个错了!(1)2x+3y=10 5z+2x=63y+5z=4 (1)x-2y=-9,y-z=3,2z+x=47.(2)3x-y+z=4,2x+3y-z=12,x+y+z=6.(3)x+2y=4,2x+3x=13,3y+z=6.(4)5x+6y+2z=80,4x-3y+z=16,3x-2y+6z=92.(5)x:y=5:3,x:z=7:2,x-3y+3z=4每个都是方程组,我不会打大括号顺便告诉我方法是什么 (3)的方程打错了 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 解方程组 x+y+z=5 2x-y-z=4 3x-2y-z=9 2x+3y-z=9,x+y+z=15,5x-4y-z=0 x+y+z=-5,3x+y+z=1,4x+3y+2z=-2快