Question

Arata ca :
1 / ( 1+ x) + 1 / ( 1+y ) + 1 / ( 1 + z) < 2
pt orice x,y,z > 0, reale cu propietatea ca x*y*z=1
multumesc anticipat!

Answer 1

x*y*z=1⇒x=1
               y=1
               z=1

1/(1+1)+1/(1+1)+1/(1+1)<2
1/2+1/2+1/2<2
0,5+0,5+0,5<2
1,5<2(Adevarat)