cmr
a, 1/2<1/51+1/52+....+1/100<1
b 7/12<1/21+1/22+....+1/40<1/10
Bài 4 :
a,Cho A= 1/2!+1/3!+.....+1/100!
CMR A<1
b, CMR :1-1/2+1/3-1/4+...+1/99-1/100=1/51+1/52+....+1/100
cho S = 1/51+1/52+...+1/100. CMR 7/12<S<5/6
A = 1/51 +1/52 + 1/53 + ... + 1/100
B = 1/1.2 + 1/3.4 + 1/4.5 + ... + 1/99.100
CMR A : B = 1
Làm mà t thấy hợp lí cho tick
CMR(1/1*2+1/2*3+1/3*4+1/4*5+...+1/99*100):(1/51+1/52+1/53+...+1/100) = 1
C/M:
a) 1/2<1/51+1/52+..+1/100<1
b) 7/12<1/21+1/22+...+1/40<5/6
chứng minh
a) 1/2 < 1/51 + 1/52 +....+ 1/100 < 1
b) 7/12 < 1/21 + 1/22 + ...+ 1/40 < 5/6
b = 2021 /51 + 2021/52 + 2021/53 + .......+ 2021/100 .cmr b > 1
CMR:\(\dfrac{7}{12}< \dfrac{1}{51}+\dfrac{1}{52}+...+\dfrac{1}{100}< \dfrac{5}{6}\)
giúp mk nhé
