Tuyển Cộng tác viên Hoc24 nhiệm kì 26 tại đây: https://forms.gle/dK3zGK3LHFrgvTkJ6
a)1/24+1/60+1/120+...+1/6840
b)1.2+2.3+3.4+2010.2011
1/1.2+1/2.3+1/3.4+...+1/59.60= /60
Bài 1:Tính:
a,3 14/19 + 13/17 + 35/43 + 6 5/19 + 8/13
b,130 25/28 + 120 17/35
c,17 2/31 - (15/17 + 6 2/31)
d,(31 6/13 + 5 9/41) - 31 6/13
e,(17 24/31 - 3 7/8) - (2 38/31 - 4)
g,1/1.2 + 1/2.3 + 1/3.4 + 1/4.5 + 1/5.6
h,1/1.2 + 1/2.3 + 1/3.4 + .........+ 1/49.100
i,1/1.3 + 1/3.5 + 1/5.7 +........+ 1/97.99
Bài 6 : Tính tổng.
a,1/8 + 1/24 + 1/48 +......+ 1/10200
b,3/1.2 + 3/2.3 + 3/3.4 +......+ 3/2015.2016
Tính nhanh
C=1.2+2.3+3.4+...+2014.2015
K=1.2+2.3+3.4+..+(n-1).n
cho A = 1/1.2+1/2.3+1/3.4+...+1/49.50 ; cho B = 1.2+1.3+3.4+....+49.50
tính 50mủ 2A - B/17
Tính nhanh A = 1/1.2 + 1/2.3 + 1/3.4 + 1/3.4 + ... + 1/49.50
1/1.2+1/2.3+1/3.4+...+1/99.100
1/1.2+1/2.3+1/3.4+…+1/2021.2022