Răspunsuri

2014-10-05T10:45:23+03:00
X+y+z≥√xy+√yz+√zx / *2
2x+2y+2z≥2√xy+2√yz+2√zx
2X+2y+2z-2√xy-2√yz-2√zx≥0
(√x-√y)²+(√y-√z)²+(√z-√x)²≥0