Ta có: \(\frac{ab}{b}=\frac{bc}{c}\Leftrightarrow\frac{ab}{bc}=\frac{b}{c}\Leftrightarrow\frac{a}{c}=\frac{b}{c}\Leftrightarrow a=b\left(1\right)\)
\(\frac{bc}{c}=\frac{ca}{a}\Leftrightarrow\frac{bc}{ca}=\frac{c}{a}\Leftrightarrow\frac{b}{a}=\frac{c}{a}\Leftrightarrow b=c\left(2\right)\)
Từ (1) và (2) => a = b = c
Vậy a = b = c