x=2y-9z x+2y-3z=2 x-2y+6z=1
来源:学生作业帮助网 编辑:六六作业网 时间:2025/01/21 14:09:14
x=2y-9zx+2y-3z=2x-2y+6z=1x=2y-9zx+2y-3z=2x-2y+6z=1x=2y-9zx+2y-3z=2x-2y+6z=1x=2y-9z即:x-2y+9z=0①x+2y-3
x=2y-9z x+2y-3z=2 x-2y+6z=1
x=2y-9z x+2y-3z=2 x-2y+6z=1
x=2y-9z x+2y-3z=2 x-2y+6z=1
x=2y-9z
即:x-2y+9z=0①
x+2y-3z=2 ②
x-2y+6z=1③
①+②
2x+6z=2
x+3z=1④
②+③
2x+3z=3⑤
⑤-④
x=2
∴2+3z=1
z=-1/3
代x=1;z=-1/3入①
1-2y-3=0
y=-1/2
即:方程组的解为x=2;y=-1/2;z=-1/3
(1)x=2y-9z
(2)x+2y-3z=2
(3)x-2y+6z=1
由(1)得x-2y=-9z带入(3)得,-3z=1,z=-1/3
由(1)(2)得x=2,y=-1/2
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z
已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX..
X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z
证明 :x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0
x+2y=3x+2z=4y+z 求x:y:z
x/2=y/3=z/5 x+3y-z/x-3y+z
x+y/2=z+x/3=y+z/4 x+y+z=27
若x+y+z=3y=2z,则x/x+y+z=?
用行列式的性质证明:y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证?
(x-2y+z)(x+y-2z)分之(y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之(x-z)(y-z)=?第三部分那个是 (y+z-2x)(x-2y+z)分之(x-z)(y-z)
已知:x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值.
x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值
x+y=5 2x+3y-z=9 x-y+z=4
已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值
已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
X=3z X+y+z=12 X+2y-2z=10