Question

chứng minh rằng:    

      M= 1/1.2   + 1/2.3  +   1/3.4   +1/4.5  +  1/5.6   +  1/6.7     <    1

 

Answer 1

\(M=\frac{1}{1.2}+\frac{1}{2.3}+.....+\frac{1}{6.7}\)

\(M=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+....+\frac{1}{6}-\frac{1}{7}\)

\(M=1-\frac{1}{7}\)

\(M=\frac{6}{7}\)

mà \(\frac{6}{7}< 1\)

\(\Rightarrow M< 1\)

Answer 2

ko bít

Answer 3

đề sai kìa

Answer 4

M=\(\frac{6}{7}\) đó .

Answer 5

Ta có: M=1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7

   = 1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7

   = 1-1/7

   =6/7<1

=> M<1

Vậy ĐPCM

T i c k giúp nha

Answer 6

M = 6 / 7 nha

Answer 7

thank you