cho x;y;z;t la 4 so khac 0 va thoa man cac dieu kien sau:
y^2=xz, z^2=yt, vay^3+z^3+t^3kac 0chung minh rang:
(y^3+z^3+x^3)/y^3+z^3+t^3=x/t
Tim 3 so nguyen to lien tiep x,y,z (x<y<z) thoa man A = x^2 + y^2 + z^2 la so nguyen to
cho cac so x,y,z va x+y+z khac 0 thoa man dieu kien
\(\frac{x+2y}{x+2y-z}+\frac{y+2z}{y+2z-x}+\frac{z+2x}{z+2x-+y}\)
tinh gt bieu thuc \(T=\frac{x^2+y^2}{xy}+\frac{y^2+z^2}{yz}+\frac{z^2+x^2}{zx}\)
tim x,y,z thoa man x/y+y/z+z/x=y/x+z/y+x/z=x+y+z=3
cho x,y,z thoa man x^2=yz;y^2=xz;z^2=xy CMR x=y=z
Cho x, y, z thoa man
x/2= y/5= z/7(y, x, z khac 0)
Tinh
P=(x-y+z)/(x-y*z-2)
tim cac so nguyen x ,y,z thoa man /x-y/+/y-z/+/z-x/=2015
tim x;y;z thoa man :5x-3y/4=2z-3x/5=9y-10z/7;2y-z=132
tim x;y;z thoa man :x+3y/19=3y+9z/114=5z+15x;x+y+2z=-31
cho xyz la cac so thuc thoa man y+z+1/x=x+z+2/y=x+y+2/z=1/x+y+z tinh gia tri bieu thuc A=2016.x+y^2017+z^2017
