MathDB
Regional Olympiad - FBH 2018 Grade 9 Problem 1

Source: Regional Olympiad - Federation of Bosnia and Herzegovina 2018

September 18, 2018
algebraidentityreal numbers

Problem Statement

if aa, bb and cc are real numbers such that (ab)(bc)(ca)0(a-b)(b-c)(c-a) \neq 0, prove the equality: b2c2(ab)(ac)+c2a2(bc)(ba)+a2b2(ca)(cb)=ab+bc+ca\frac{b^2c^2}{(a-b)(a-c)}+\frac{c^2a^2}{(b-c)(b-a)}+\frac{a^2b^2}{(c-a)(c-b)}=ab+bc+ca