\(C=\dfrac{4}{1.3}.\dfrac{9}{2.4}.\dfrac{16}{3.5}.\dfrac{25}{4.6}....\dfrac{9801}{9800}=\)
\(=\dfrac{2^2.3^2.4^2.5^2.....99^2}{1.2.3^2.4^2.5^2....98^2.99.100}=\dfrac{2.99}{100}=\dfrac{198}{100}=1,98\)
1/1.3-1/2.4+1/3.5+1/4.6+...+1/97.99-1/98.100 = ?
1/1.3+1/2.4+1/3.5+.....+1/97.99+1/98.100-49/99=
1/(1.3)+1/(2.4)+1/(3.5)+1/(4.6)+...+1/(2021.2023)
Tính \(\frac{1}{3.1}-\frac{1}{2.4}+\frac{1}{3.5}-\frac{1}{4.6}+...+\frac{1}{97.99}-\frac{1}{98.100}\)
Tính giá trị biểu thức:
1/ 1.3 + 1/2.4 + 1/3.5 + 1/4.6 + 1/5.7 + 1/6.8 + 1/7.9 + 1/8.10
tính tổng
S=\(\dfrac{1}{1.3}-\dfrac{1}{2.4}+\dfrac{1}{3.5}-\dfrac{1}{4.6}+\dfrac{1}{5.7}-\dfrac{1}{6.8}+\dfrac{1}{7.9}-\dfrac{1}{8.10}\)
giúp nha
Chứng minh rằng: 1/1.3 + 1/2.4 + 1/3.5 + 1/4.6 + ...+ 1/2013.2015 + 1/2014.2016 < 3/4
Giúp!!!!!!!!
Tính nhanh
1,
A = \(\frac{1}{1.3}-\frac{1}{2.4}+\frac{1}{3.5}-\frac{1}{4.6}+..........+\frac{1}{97.99}-\frac{1}{98.100}\)
2,
B=
\(1+\frac{1}{2}.\left(1+2\right)+\frac{1}{3}.\left(1+2+3\right)+.........+\frac{1}{20}.\left(1+2+3+.........+20\right)\)
Tính tổng: \(S=\frac{1}{1.3}-\frac{1}{2.4}+\frac{1}{3.5}-\frac{1}{4.6}+\frac{1}{5.7}-\frac{1}{6.8}+\frac{1}{7.9}-\frac{1}{8.10}\)
