chứng minh rằng:1/1.3 + 1/2.4 + 1/3.5 + 1/4.6 +....+ 1/97.99 + 1/98.100 < 3/4
chứng minh rằng 1^1.3 + 1^2.4 + 1^3.5 + 1^4.6 +...+ 1^97.99+ 1^98.100 < 3^4
Chứng minh rằng: \(\frac{1}{1.3}+\frac{1}{2.4}+\frac{1}{3.5}+\frac{1}{4.6}+...+\frac{1}{97.99}+\frac{1}{98.100}< \frac{3}{4}\)
tính C=1.3+2.4+3.5+4.6+.....+(n-1).(n+1)
bai1:tinh tong S=1.3+3.5+5.7+...+99.101
bai2 :tinh tong S=1.4+4.7+7.10+...+2017.2020
bai 3: tinh tong N=2.4+4.6+6.8+..+100.102
bai 4: tinh tóng=2.6+6.10+10.14+14.18+...+42.46+50.54
bai 5:tinh tongB=2^2+4^2+6^2+...+100^2
bai 6:C=1^2+3^2+...+100^2
bai7: biet 1^2+2^2+3^2+...+10^2=385 tinh tong 2^2+4^2+6^2+...+20^2
bai 8: tinh tong s=1^2+2^2+3^2+...+99^2
Tính:
\(B=\left(1+\frac{1}{1.3}\right)\left(1+\frac{1}{2.4}\right)\left(1+\frac{1}{3.5}\right)...\left(1+\frac{1}{2016.2018}\right)\)
1/1.3-1/2.4+1/3.5-1/4.6+...+1/97.99-1/98.100 = ?
(1+1/1.3)(1+1/2.4)(1+1/3.5)(1+1/4.6)...(1+1/2013.2015