Các câu hỏi tương tự
Cho B= 1/4+1/5+1/6+...+1/19. CMR B>1
CMR: 1/4+1/5+1/6+...+1/19>1
CMR
1-1/2+1/3-1/4+1/5-1/6+...+1/19-1/20=1/11+1/12+...+1/21
CMR
1-1/2+1/3-1/4+1/5-1/6+...+1/19-1/20=1/11+1/12+...+1/21
CMR : 1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + ... + 1/19 - 1/20 = 1/11 + 1/12 + 1/13 + ... + 1/20
Xem chi tiết
CMR
\(\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+.......+\frac{1}{19}>1\)
CMR:
1-\(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}...+\frac{1}{19}-\frac{1}{20}=\frac{1}{11}+\frac{1}{13}+...+\frac{1}{20}\)
Cho B=\(\frac{1}{4}+\frac{1}{5}+...+\frac{1}{19}\)
CMR B nhỏ hơn 1
B1.Tìm A/B biết:
A=4/(7*31)+6/(7*41)+9/(10*41)+7/(10*57)
B=7/(19*31)+5/(19*43)+3/(23*43)+11/(23*57)
B2:CMR:
A=1/52+2/53+3/54+...+11/512 <1/16