Revision as of 10:50, 3 July 2016 by Pega969(talk | contribs)(Created page with "=== Problem 20 === If <math>a,b,c</math> are non-zero real numbers such that <math>\frac{a+b-c}{c}=\frac{a-b+c}{b}=\frac{-a+b+c}{a}</math>, and <math>x=\frac{(a+b)(b+c)(c+a)...")