MathDB
Given two equal quantities, show they are both x+y+z

Source: Finland 2012, Problem 2

May 5, 2013
algebra unsolvedalgebrasystem of equations

Problem Statement

Let x1,y1x\ne 1,y\ne 1 and xy.x\ne y. Show that if yzx21x=zxy21y,\frac{yz-x^2}{1-x}=\frac{zx-y^2}{1-y}, then yzx21x=zxy21y=x+y+z.\frac{yz-x^2}{1-x}=\frac{zx-y^2}{1-y}=x+y+z.