IMO 1969 LL USS67
Under the conditions x1, x2 > 0, x1y1 > z2
IMO 1969 LL USS67
Origin: USS
Problem
Under the conditions x1, x2 > 0, x1y1 > z2 1, and x2y2 > z2 2, prove the inequality (x1 + x2)(y1 + y2) −(z1 + z2)2 \leq x1y1 −z2 + x2y2 −z2 .
Under the conditions x1, x2 > 0, x1y1 > z2
Origin: USS
Under the conditions x1, x2 > 0, x1y1 > z2 1, and x2y2 > z2 2, prove the inequality (x1 + x2)(y1 + y2) −(z1 + z2)2 \leq x1y1 −z2 + x2y2 −z2 .