解方程组x:y:z=1:2:3,x y z=36
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/24 21:48:37
x+2y+3z=80.1,x/2+y/3=z/4.2由2式得:6x+4y=3z代入1式得:7x+6y=80解有无数组,如:x=2,y=11,z=56/3x=4,y=26/3,z=176/9x=8,y=
①式+②式得x-y=5……④①式+③式得2x-5y=4……⑤2×④式-⑤式得y=2将y=2带入④式得x=7带入①式可得z=-2即x=7y=2z=-2
解由2x+3y+z=11.①x+y+z=0.②3x-y+z=-2.③由(1)-(2)得x+2y=11.④由(2)-(3)得-2x+2y=2.⑤由(4)-(5)得3x=9即x=3把x=3代入④中解得y=
{3x+y-z=4①,2x-y+3z=12②,x+y+z=6③}①+②得5x+2z=16④,②+③得3x+4z=18⑤④×2—⑤得7x=14,x=2所以z=3、y=1所以方程组的解为x=2、y=1、z
2x+y=4(1),x+3z=1(2),x+y+z=7(3)由(2)得x=1-3z(4)将(4)代入(1)得2(1-3z)+y=4y=2+6z(5)将(4)(5)代入(3)得(1-3z)+(2+6z)
设X为2a,Y为3a,Z为5a2*2a+3*3a-5a=16得a=2所以X=4Y=6Z=10
x+2y-z=1,3x-3y+z=2两式相加得出:4x-y=3,前式乘以5得出20x-5y=15;x+2y-z=1,2x+3y+z=7两式相加得出:3x+5y=8;20x-5y=15与3x+5y=8相
设(x+y)/2=(x+z)/3=(y+z)/4=k则x+y=2kx+z=3ky+z=4k代入x+y+z=272k+3k+4k=27k=3所以x+y=6(1)x+z=9(2)y+z=12(3)(1)+
由x:y=2:1得x=2y,代入2x-y=3z,可得3y=3z,z=y于是x+y+z=2y+y+y=20,y=5,x=10,z=5于是x=10,y=5,z=5
x=2y;2y=3z;z+2x+3y=23;x=6;y=3;z=2;
x+y+z=41式x+y+2z=52式3x+y-z=63式2-1式z=13-2式2x-3z=14式z=1代入4式x=2再代入1式y=1∴x=2,y=1,z=1请点击下面的【选为满意回答】按钮,再问:�
X:Y:Z=1:2:3则Y=2X,Z=3X代入X+Y+Z=12,得X+2X+3X=12解得X=2,则Y=2X=4Z=3X=6
z=x+y(1)3x-2y-2z=-5(2)2x+y-z=3(3)由(1)得x+y-z=0(4)(3)-(4)得x=3把x=3代入(2)得9-2y-2z=-5y+z=7(5)把x=3代入(4)得y-z
x:y=1:2y=2xx:z=1:3z=3x2x+y-3z=152x+2x-9x=15-5x=15x=-3y=-3x2=-6z=-3x3=-9如果本题有什么不明白可以追问,
1式-3式得到y=12式+3式得到x=2知道了x,y带入任意方程可得到z=-2
2x+y-3z=1,①x-2y+z=6,②3x-y+2z=9③①+③得:5x-z=10④①×2+②得:5x-5z=8⑤④-⑤得:4z=2∴z=1/2x=21/10=2.1y=-1.7
设x=my=2mz=3mm+2m+3m=366m=36m=6x=6y=6*2=12z=6*3=18
x-2y+z=-1①x+y+z=2②x+2y+3z=-1③①+③2x+4z=-2x+2z=-1④①+②×23x+3z=-1+4x+z=1⑤由⑤得x=1-z代入④1-z+2z=-1z=-2∴x=1-(-
x+y-z=0(1)x+2y-z=3(2)2x-3y+2z=5(3)2-1式得y=3将y=3代入2、3得x-z=-3(4)x+z=7(5)4+5式得2x=4解得x=2y=5综合得x=2y=3z=5
由x:y:z=1:2:3可得y=2x,z=3x代入x+y+z=36得6x=36于是x=6,y=12,z=18