(1)(1/X+4/Y+9/Z)*(X+Y+Z)≥（1+2+3）²是咋用柯西不等式算出来的!(2) K≥2 求证K+1/K≥5/2(3)|x+1/x|的取值范围

x,y,z都>0.且x+y+z=1.求证1/x+4/x+9/z>=36 12y+9z=x,6(y+1/4)+9z=x,y+z=x 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) ..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 4x-9z=17 3x+y+15z=18 x+2y+3z=2x+y+z=26 x-y=1 2x+z-y=18 解下列三元一次方程组:(1)x-z=4,x+y-z=-1,2y-z=1 (2)3x+4z=7,2x+3y+z=9,x-y+z=8 x+4y+9z=1,求x^2+y^2+z^2的最小值 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 三元一次方程组(1)x-2y=-9 y-z=3 2z+x=47 (2)3x-y+z=4 2x+3y-z=12 x+y+z=6 3元1次方程x-2y=-9 3x-y+z=4{ y-z=3 { 2x+3y-z=122z+x=47 x+y+z=6 设x,y.z为实数,2x.3y.4z是等比数列,1/x,1/y.1/z是等差数列,则(x/z)+(z/x)是多少? 3x+2y+z=9 x-3y-2z=1 -x+4y=5 3x-2y=-4;2x+3y+z=9;x-2y+z=-1 解方程组2x+y-3z=1,x-2y+z=6,3x-y+2z=9求x,y,z的值解方程组6x+y-z=0,3x-y+z=5,y+2z=4求x,y,z的值 真的实在解不出来,希望你能帮帮忙! 分解因式 4a（x-y）²-a²（y-x）³ （x+y+z)（x-y+z）+(y-x+z) (y-x-z)（1）4a（x-y）²-a²（y-x）³ （2）（x+y+z)（x-y+z）+(y-x+z) (y-x-z) 数学题在线解答：三元一次方程组；(1)X+Y+Z=0,4X+2Y+Z=0,Z=2;(2)9X+3Y+Z=0,X-Y+Z=0,Z=-3,(3)4X+2Y+Z=5,4X-2Y+Z=1Z=-1;(5)5X+2Y+Z=12,4X+3Y+Z=13,Z=3 x-z=-4 z-2y=-1 x+y-z=-1 怎么解