Cho x,y,z khac nhau va :1/x+1/y+1/z=1/x+y+z
CMR trong 3 so x,y,z co it nhat 1 cap so doi nhau
Cho x y z la cac so huu ti doi mot khac nhau va khac khong thoa man x+1/y=y+1/z=z+1/x Chung minh xyz=1 hoac xyz=-1
cho ba so x,y,z khac 0 thoa man x+y+z=2015 va 1/x+1/y+1/z=1/2015 chung minh ba so x,y,z khong ton tai 2 so doi nhau
Cho 1/x+1/y+1/z=0 (x; y; z khác 0). Chứng minh rằng: 1/x^2+1/y^2+1/z^2=3/xyz
Cho 1/x + 1/y + 1/z = 0. Chung minh xyz(1/x^3 + 1/y^3 + 1/z^3) = 3 .
cho x,y,z duong va x+y+z=1. chung minh rang 1/x^2+2yz+1/y^2+2xz+1/z^2+2xy>=9
thank, giup minh mik cho 3 tick
cho x^2+y^2+z^2=5/2 va x,y,z>0 cm 1/x+1/y<1/xyz+1/z\(cho x^2+y^2+z^2=5/2 va x,y,z>0 cm 1/x+1/y<1/xyz+1/z\)
cho x,y,z>0 thoa man x+y+z<=1 chung minh rang 17(x+y+z)+2(1/x+1/y+1/z)=>35
cho 3 so x, y, z khong am. Chung minh:
\(\left(x+1\right)\left(y+1\right)\left(z+1\right)\ge\left(1+\sqrt[3]{xyz}\right)^3\)