A, CHO A, B, C > 0        CMR

Câu 2:

a, Cho a, b, c > 0

  

CMR:

a b

2

2

b c

2

2

a c

2

2

1

1

1

a

b

b

c

a

c

a

b

c

b, Cho 0

a, b, c

1

CMR: a+b+c+

1

abc

1

1

1

a

 

b

c

+ abc