已知{3X-4y-z=0 2x+y-8z=0 ,求x(x^2+y^2+z^2)/(xy+yz+2zx)的值,请写出过程.
来源:学生作业帮助网 编辑:作业帮 时间:2024/04/24 23:15:50
xRJA~v7sV9
BffJMB$Eo..f9L*gywbZ n gPfp+zt"lأXq
79N
P,fE?L>i,NSWznsPmݗ T7e.+GY7$U^P(ECr *͖gS8*ZQ!IaQڈE))'P~m!ěTX!Ĉm
tP Ke5q(rxKlz nP@nf"b7r?L/Rݒycǎw^*+&̱=Er
Z_7X'kv
*Ь4i
已知{3X-4y-z=0 2x+y-8z=0 ,求x(x^2+y^2+z^2)/(xy+yz+2zx)的值,请写出过程.
已知{3X-4y-z=0 2x+y-8z=0 ,求x(x^2+y^2+z^2)/(xy+yz+2zx)的值,请写出过程.
已知{3X-4y-z=0 2x+y-8z=0 ,求x(x^2+y^2+z^2)/(xy+yz+2zx)的值,请写出过程.
用其中一个变量表示另外两个变量,然后代入那个式子,再化简约分.
由3x-4y-z=0得z=3x-4y
由2x+y-8z=0得y = 8z-2x = 8(3x-4y) -2x = 22x - 32y 即33y = 22x
于是y = 2x / 3,z = 3x - 4 * 2x / 3 = x / 3
不过我算的答案是x,不知道问题出在哪儿,或者答案不对.
由3x-4y-z=0得z=3x-4y ③
由2x+y-8z=0得y=8z-2x ④
④代入③得 x=3z ⑤
y=2z
将x,y代入
(x^2+y^2+z^2)/(xy+yz+2zx)
=(9z^2+4z^2+z^2)/(6z^2+2z^2+6z^2)
=(14z^2)/(14z^2)
=1
已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX..
已知4x-3y+z=0,x+2y-8z=0,xyz不等于0,求x+y-z/x-y+2z的值
已知3x-4y-z=0,2x+y-8z=0,且z≠0,则x:y:z=( )
已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=?
已知x-2y+3z=0,x-3y+4z=0,则x:y:z=
已知2x-y-z=0,3x+4y-2z=0,则x:y:z=?
已知x+4y-3z=0,4x-5y+2z=0,则x:y:z
已知{x-5y+2z=0 3x-5y-4z=0,求x:y:z
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
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
已知:4x-5y+2z=0 x+4y-3z=0则:(x*x+y*y+z*z)/(x*y+y*z+z*x)=____.
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.
已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z
已知方程组4x-3y-2z=0,x-3y+z=0,z≠0求x/z,y/z的值
三元一次方程组题目x+y-z=11 y+z-x=5 x-y+z=1x+y=4 y+z=3 x+z=5若已知x-3y+2z=0 2x+3y-8z=0, 且xyz≠0,则x:y:z=
已知x+2y-4z=0,3x-y-z=0,则3x+2y+z/x+2y+z=
已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z
已知4X-3y-3z=0 X-3y-Z=0求3X-2Z+Y/-x+y+Z的值