MathDB
a+b=c+d and a^2+b^2=c^2+d^2

Source: Romanian MO 2010 Grade 8

August 6, 2012
number theory proposednumber theory

Problem Statement

How many four digit numbers abcd\overline{abcd} simultaneously satisfy the equalities a+b=c+da+b=c+d and a2+b2=c2+d2a^2+b^2=c^2+d^2?