1/1x2+1/2x3+1/3x4+...+1/99x100+1/100x101
=1/1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100+1/100-1/101
=1/1-1/101
=100/101
1/1x2+1/2x3+1/3x4+...+1/99x100+1/100x101
=1/1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100+1/100-1/101
=1/1-1/101
=100/101
tính (1-2/6).(1-2/12).(1-2/20)...(1-2/9900)
tìm B=(1/2+1/6+1/12+...+1/9900)/(1/51+1/52+1/53+...+1/100)
1.Tính A=1/4+1/12+1/24....+1/20200
B=1/2+5/6+11/12+....+9899/9900
2.CMR:1/1.2+1/3.4+1/5.6+.....+1/49.50=1/26+1/27+...+1/50
\(\left(1-\frac{2}{6}\right)\times\left(1-\frac{2}{12}\right)\times\left(1-\frac{2}{20}\right)...\left(1-\frac{2}{9900}\right)\) Tính
Tính :\(B=\left(1-\frac{2}{6}\right)\times\left(1-\frac{2}{12}\right)\times\left(1-\frac{2}{20}\right)\times...\times\left(1-\frac{2}{9900}\right)\)
1/2+1/12+1/30+...+1/9120+1/9506+1/9900. / 50-50/51-51/52-...-97/98-98/99-99/100
Cho A = \(\frac{2^2-1^2}{2^2}+\frac{3^2-2^2}{6^2}+\frac{4^2-3^2}{12^2}+.....+\frac{100^2-99^2}{9900^2}\)
Chứng minh A < 1
tính
\(B=\frac{1+2+2^2+2^3+...+2^{2008}}{1-2^{2009}}\)
\(B=\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+...+\frac{1}{9900}\)
bạn nào lm nhanh đc nhìu tick nè
A=1/2+1/6+...+1/9900
B=1/50+1/51+...+1/100
Tính A-B