MathDB
System with 2024 variables, but how many are equal?

Source: Francophone 2024, Junior P1

April 4, 2024
algebra proposedsystem of equationsalgebra

Problem Statement

Find the largest integer kk with the following property: Whenever real numbers x1,x2,,x2024x_1,x_2,\dots,x_{2024} satisfy x12=(x1+x2)2==(x1+x2++x2024)2,x_1^2=(x_1+x_2)^2=\dots=(x_1+x_2+\dots+x_{2024})^2, at least kk of them are equal.