Question

[Hoàng Xuân Ngân]

Cho \(a^2=bd;b^2=ac;a+b+c\ne0;a^3+b^3+c^3\ne0\)

Chứng minh rằng \(\frac{d}{c}=\frac{a^3+b^3+c^3}{b^3+c^3+a^.}=\frac{\left(a+b+c\right)^3}{\left(b+c+d\right)^3}\)