MathDB
Turkey TST 1991 - P2

Source:

March 13, 2011
number theory proposednumber theory

Problem Statement

Show that the equation a2+b2+c2+d2=a2b2c2d2a^2+b^2+c^2+d^2=a^2\cdot b^2\cdot c^2\cdot d^2 has no solution in positive integers.