1tính tổng

A =(1-1/2)+(1-1/6)+(1-1/12)+..+(1-1/70)

B=(1-1/3)+(1-1/15)+(1-1/35)+(1-1/63)

C=1/2+5/6+11/12+....+8998/9900

D=2/3+14/15+34/35+...+1119/1120

E=9/10+39/40+87/88+....+9998/9999

F=10/56+10/140+10/260+...+10/1400

G=1/1.2.3+1/2.3.4+1/3.4.5+1/+4.5.6+...+1/8.9.10

H=2/2007+2/60.63+2/63.66+...+2/117.120

I=1-1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2

mình cần gấp mông mọi người giúp nha !

Tính B=1-10/56-10/140-10/260-...-10/1400

A=15/90.94+15/94.98+15/98.102+....+15/146.150

B=10/56+10/140+10/260+...+10/1400

C=1/25.27+1/27.29+1/29.31+.....+1/73.75

cho A=-10/56+-10/140+-10/260+......................+-10/1400. so sánh A với B=-1/3

Bài 1: Tính K =\(\frac{10}{56}+\frac{10}{140}+\frac{10}{260}\)+...+\(\frac{10}{1400}\)

Bài 2: Cho M =\(\frac{1}{2}+\frac{1}{12}+\frac{1}{30}+...+\frac{1}{9900}\).CMR: M<\(\frac{5}{6}\).

1, Tính tổng 

A= 10/56 + 10/140 + 10/260 +....+ 10/1400

cho biểu thức A=-10/56+-10/140+-10/260+...+-10/1400.so sánh A với -1/3

Cho biểu thức A = 10/56 + 10/140 + 10/260 + ......... + 10/1400. So sánh A với 1/3.

bài 1

a,F=1/25.27 +1/​​27.29 +.....+1/73.75

b,G=15/90.94 +15/94.98 +.....+15/146.150

c,H=10/56+10/140 +10/260+....+10/1400