Problem

Source: 2018 Romania JBMO TST 3.1

Tags: system of equations, algebra



Determine all triples of real numbers $(a,b,c)$ that satisfy simultaneously the equations: $$\begin{cases} a(b^2 + c) = c(c + ab) \\ b(c^2 + a) = a(a + bc) \\ c(a^2 + b) = b(b + ca) \end{cases}$$