\(\left(1+\dfrac{1}{2^2}\right)+\dfrac{1}{2}\cdot8,88-\dfrac{12}{56}\)
\(=1,25+4,44-\dfrac{3}{14}\)
\(=5,69-\dfrac{3}{14}=\dfrac{3833}{700}\)
Tính
1. A= 1/2+1/6+1/12+/1/20+1/30+1/42+1/56
2. B = 3/2+5/6+7/12+-9/20+11/30-13/42+15/56
Tính nhanh
a)A = 1 + 1/2 +1/4 + .......+ 1/2^99 +1/2^100+1/2^100
b) 12/56 + 12/140+12/260 +.....+ 12/1400
1/2 + 1/6 +1/12 +1/20 + 1/30 +1/42+ 1/56
tinh giùm cái A= 1/2+ 1/6 + 1/12 + 1/12 + 1/30 + 1/42 + 1/42 + 1/56 + 1/72
Tính: 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56
1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 = ?
8/9 - 1/72 - 1/56 - 1/42 - 1/30 - 1/20 - 1/12 - 1/6 - 1/2
tính
A=1/12+1/20+1/30+1/42+1/56+1/72
B=2/1.4+2/4.7+2/7.10+2/10.13+2/13.16
tính 1/90-1/2-1/56-1/42-1/30-1/20-1/12-1/6-1/2.
MONG CÁC BẠN GIÚP ĐỠ
9/10-1/90-1/72-1/56-1/42-1/30-1/20-1/12-1/6-1/2 = ?
