MathDB
Numbers in the set {-1,1} such that sum of pairs is 999

Source: Pan African Olympiad 2009

October 1, 2011
number theory proposednumber theory

Problem Statement

Determine whether or not there exist numbers x1,x2,,x2009x_1,x_2,\ldots ,x_{2009} from the set {1,1}\{-1,1\}, such that: x1x2+x2x3+x3x4++x2008x2009+x2009x1=999x_1x_2+x_2x_3+x_3x_4+\ldots+x_{2008}x_{2009}+x_{2009}x_1=999