A=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+...+1/9-1/10
A=1-1/10=9/10
B=1/6.10+1/10.6+1/7.9+1/9.7+1/8.8
B=1/30+2/63+1/64
B=1627/20160
A:B=9/10:1627/20160=1/22400
Tính A : B biết:
\(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+\frac{1}{7.8}+\frac{1}{9.10}\) và \(B=\frac{1}{6.10}+\frac{1}{7.9}+\frac{1}{8.8}+\frac{1}{9.7}+\frac{1}{10.6}\)
Tính Tỉ Số A và B biết :
A = \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.....+\frac{1}{9.10}\)
B = \(\frac{1}{6.10}+\frac{1}{7.9}+\frac{1}{8.8}+\frac{1}{9.7}+\frac{1}{10.6}\)
1) Cho :
A= 1/(1.2)+1/(3.4)+1/(5.6)+...+1/(9.10) va B= 1/(6.10)+1/(7.9)+1/(8.8)+1/(7.9)+1/(10.6)
Tinh A:B
2) Cho P= (1/2).(3/4).(5/6). ... .(99/100). CMR: 1/15< P<1/10
tính B=1/6.10+1/7.9+1/8.8+1/9.7+1/10.6
tính: 1/6.10 + 1/7.9 + 1/8.8 + 1/9.7 + 1/10.6
A=1/ 6.10+1/ 7.9+1/ 8.8+1/ 9.7+1/ 10.6
Chứng minh rằng: A=1/8. (1/6+1/7+1/8+1/9+1/10)
A=1/ 6.10+1/ 7.9+1/ 8.8+1/ 9.7+1/ 10.6
Chứng minh rằng: A=1/8. (1/6+1/7+1/8+1/9+1/10)
\(\frac{1}{6.10}+\frac{1}{7.9}+\frac{1}{8.8}+\frac{1}{9.7}+\frac{1}{10.6}=\)?
Tính A = 1/1.2 + 1/3.4 + 1/5.6 + 1/7.8 + 1/9.10
