Question

Cho \(\left(x+y+z\right)\left(xy+yz+z\right)=xyz\)

Chứng minh rằng: \(x^{2017}+y^{2017}+z^{2017}=\left(x+y+z\right)^{2017}\)

Answer 1

Ta có:

\(\left(x+y+z\right)\left(xy+yz+zx\right)=xyz\)

\(\Leftrightarrow\left(x+y\right)\left(y+z\right)\left(z+x\right)=0\)

\(\Leftrightarrow x=-y;y=-z;z=-x\)

Với \(x=-y\)

\(\Rightarrow x^{2017}+y^{2017}+z^{2017}=z^{2017}=\left(x+y+z\right)^{2017}\)

Tương tự cho 2 trường hợp còn lại