x平方-{y-z}的平方分之{x y}的平方-z的平方
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3xy²/z³*8x³/y=24x的4次方y/z³再问:这个是有选项的A6xyzB12xyzC.-6xyzD.6x的平方yz再答:3xy²/z
答案是-151/891吗?
X+4Y-3Z=0(1)4X-5Y+2Z=0(2)(1)*4-(2)16Y-12Z+5Y-2Z=021Y=14ZY:Z=2:3y=2z/3(1)*5+(2)*45X-15Z+16X+8Z=021X=7
设x/2=y/3=z/4=a则:x=2a;y=3a;z=4a代入得:(xy+yz+zx)/(x^2+y^2+z^2)=(6a^2+12a^2+8a^2)/(4a^2+9a^2+16a^2)=26a^2
7x的立方y的平方,8x的立方y,2分之1x的平方y的平方,-3yx的平方z,9x的4次方zy,zy的平方,-5分之1xyz,9y的立方z,0.3z的立方一共是九项,因为9y的立方z不含x,所以所有含
x^2(y-z)+y^2(z-x)+z^2(x-y)=x^2y-x^2z+y^2z-y^2x+z^2x-z^2y=y(x^2-z^2)-xz(x-z)-y^2(x-z)=y(x+z)(x-z)-xz(
设x/2=y/3=z/4=k∴x=2k,y=3k,z=4k∴(xy+yz+zx)/(x²+y²+z²)=(6k²+12k²+8k²)/(4k
题目是否错了应该改为(x+y+z)^2-4(x-y-z)^2(x+y+z)^2-4(x-y-z)^2=[(x+y+z)-2(x-y-z)][(x+y+z)+2(x-y-z)]=(3Y+3Z-X)(3X
令3分之x=4分之y=6分之z=kx=3k,y=4kz=6k(xy+yz+xz)/(x^2+y^2+z^2)=k^2(12+18+24)/k^2(36+16+9)=54/61
令a=xx=6a.y=4a.z=3a(2x^2-yz+z^2)/(x^2-2xy+z^2)=(72a^2-12a^2+9a^2)/(36a^2-48a^2+9a^2)=69a^2/(-3a^2)=-2
(1+z)/2xyz=(1+z)(1-z)/2xyz(1-z)=(1-z^2)/2xyz(1-z)=(x^2+y^2)/2xyz(1-z)>=2xy/2xyz(1-z)=1/(-z^2+z)=1/(-
1、原式=(x-z)^2-(2y)^2-(x-z+y)^2=(2x-2z+y)(-y)-4y^2=-2xy+2yz-y^2-4y^2=-2xy+2yz-5y^22、x=4/31/x=3/41/x^2-
[x²-(y-z)²]/[(x+y)²-z²]=(x+y-z)(x-y+z)/(x+y+z)(x+y-z)=(x-y+z)/(x+y+z)再问:谢谢你!但是最终
x+2y-z=0(1)2x-2y-5z=0(2)(1)+(2)得3x-6z=0∴x=2z把x=2z代入(1)得2z+2y-z=0∴y=-z/2x的平方+2xy-3z的平方分之3x的平方-2xy+2z的
感觉是你写错了,应该是下面的这个吧(x+y-z)²-(x-y+z)²=[(x+y-z)-(x-y+z)][(x+y-z)+(x-y+z)]=(x+y-z-x+y-z)(x+y-z+
令3/x=4/y=6/z=1/k则x=3ky=4kz=6k(x²+y²+z²)/(xy+yz+xz)=(9k²+16k²+36k²)/(12
(x+y+z)²=[(x+y)+z]²=(x+y)²+z²+2(x+y)z=x²+y²+z²+2xy+2yz+2zx
13分之36再问:过程何在再答:3*(2X-3Y+Z)=02*(3X-2Y-6Z)=06X-9Y+3Z=6X-4Y-12Z5Y-15Z=0y=3Z同理2*(2X-3Y+Z)=03*(3X-2Y-6Z)
3分之x=y=2分之zx+x/3+2x/3=12x=6y=6z=02x的平方+12y的平方+9z的平方=2*6^2+12*6^2+9*0=14*36=504