Chứng minh rằng\(\left(x+y^2\right)\left(y+x^2\right)-\left(x+y\right)\left(x^2+y^2\right)=\left(xy-x\right)\left(xy-y\right)\)

Cho \(\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2=\left(x+y-2z\right)^2+\left(y+z-2x\right)^2+\left(x+z-2y\right)^2\)

Chứng minh rằng: x=y=z

Chứng minh rằng nếu:\(\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2=\left(y+z-2x\right)^2+\left(z+x-2y\right)^2+\left(x+y-2z\right)^2\)thì x=y=z

Chứng minh rằng: \(\frac{x^2-y^2}{\left(z+x\right)\left(z+y\right)}+\frac{y^2-z^2}{\left(x+y\right)\left(x+z\right)}+\frac{z^2-x^2}{\left(y+z\right)\left(y+x\right)}=\frac{x-y}{x+y}+\frac{y-z}{y+z}+\frac{z-x}{z+x}\)

cho các số dương x,y,z chứng minh rằng:

\(\dfrac{x^2}{\left(x+y\right)\left(x+z\right)}\)+\(\dfrac{y^2}{\left(y+z\right)\left(y+x\right)}\)+\(\dfrac{z^2}{\left(z+x\right)\left(z+y\right)}\)≥\(\dfrac{3}{4}\)

Chứng minh rằng:\(x^{\left(2^{y+1}\right)}+x^{\left(2^y\right)}+1=\left(x^2+x+1\right)\left(x^2-x+1\right)\left(x^4-x^2+1\right)...\left(x^{\left(2^{y-1}\right)}+x^{\left(2^{y-2}\right)}+1\right)\left(x^{\left(2^y\right)}+x^{\left(2^{y-1}\right)}+1\right)\)với mọi \(x\in N;x>0\)và \(y\in N;y>1\)

Cho \(\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2=\left(x+y-2z\right)^2+\left(y+z-2x\right)^2+\left(x+z-2y\right)^2\)

Chứng minh rằng: x=y=z

chứng minh rằng : neeus \(\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2=\left(y+z-2x\right)^2+\left(z+x-2y\right)^2+\left(x+y-2z\right)^2\)

thif x=y=z 

Chứng minh các đẳng thức sau:

a) \(\left(x^2+y^2\right)^2-\left(2xy\right)^2=\left(x+y\right)^2-\left(x-y\right)^2\)

b) \(\left(x+y\right)^3=x.\left(x-3y\right)^2+y.\left(y-3x\right)^2\)