x减4y加z=-3 2x+y-z=18 x-y-z=7 求xyz
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x减4y加z=-3 2x+y-z=18 x-y-z=7 求xyz
x减4y加z=-3 2x+y-z=18 x-y-z=7 求xyz
x减4y加z=-3 2x+y-z=18 x-y-z=7 求xyz
一加三
2x-5y=4 A
二减三
x+2y=11 B
A-B*2
-9y=-7
y=7/9
代入x=85/9,z=5/3
三元一次方程而已,做法就是消元
x-4y+z=-3 ①
2x+y-z=18 ②
x-y-z=7 ③
①+②
3x-3y=15
x-y=5
将x-y=5代入③
z=-2
将z=-2代入①②
x-4y=-1④
2x+y=16⑤
④*2 2x-8y=-2⑥
⑥-⑤ -9y=-18
...
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三元一次方程而已,做法就是消元
x-4y+z=-3 ①
2x+y-z=18 ②
x-y-z=7 ③
①+②
3x-3y=15
x-y=5
将x-y=5代入③
z=-2
将z=-2代入①②
x-4y=-1④
2x+y=16⑤
④*2 2x-8y=-2⑥
⑥-⑤ -9y=-18
y=2
将y=2代入④
x=7
所以x=7,y=2,z=-2
简单吧
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x减4y加z=-3 2x+y-z=18 x-y-z=7 求xyz
x+y/2=z+x/3=y+z/4 x+y+z=27
x+2y=3x+2z=4y+z 求x:y:z
已知x/2等于y/3=z/4=k且2x-3y加z=10,则x加y加z=多少
解方程组 3x加2y加5z=2 x-2y-z=6 4x加2y-7z=30
已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
如果x/2=y/3=z/4,且x+y+z=18,那么x+y-z=?
x:y:z=3:4:7 2x-3y+z=18 求:3x-2y+z
解方程组x-4y+z=-3,2x+y-z=18,x-y-z=7.
x-4y+z=-3 2x-y+z=18 x-y-z=12
2x+z=10 x+y-z=4 3x-y-z=0
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
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
X+2Y+3Z=18 X+4Y+3Z=24 Y=?
(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=?
谁来帮我算三元一次方程Y=2X-75X加3Y加2Z=23X-4Z=4----------4X加9Y=123Y-2Z=17X加5Z=4份之19_____________4X-9Z=173X加Y加15Z=18X加2Y加3Z=2
3x-y+z=4,2z+3y-z=12,x+y+z=6的解