Question

[Nguyễn thị Hằng]

A = 1/5+1/6+1/7+1/8+1/9 .Hãy so sánh A với số 1

Answer 1

[Lê Chí Cường]

Ta thấy: 1/6<1/5

               1/7<1/5

               1/8<1/5

               1/9<1/5

=>A=1/5+1/6+1/7+1/8+1/9<1/5+1/5+1/5+1/5+1/5

=>A<5.1/5

=>A<1

Vậy A<1