MathDB

007

Part of 1961 All Russian Mathematical Olympiad

Problems(1)

ASU 007 All Russian MO 1961 9.2 & 10.3 numbers in a table

Source:

6/17/2019
Given some m×nm\times n table, and some numbers in its fields. You are allowed to change the sign in one row or one column simultaneously. Prove that you can obtain a table, with nonnegative sums over each row and over each column.
combinatoricstable