\(A=\frac{1}{7}\left[\frac{1}{2}-\frac{1}{9}+...+\frac{1}{252}-\frac{1}{509}\right]\)
\(A=\frac{1}{7}.\left[\frac{1}{2}-\frac{1}{509}\right]\)
\(A=\frac{1}{7}.\left[\frac{507}{1018}\right]=\frac{507}{7126}\)
mk nghĩ là vậy đó, ủng hộ mk nha
1/2.9+1/9.7+1/7.19+..........+1/252.509 = ?
1/2.9+1/9.7+1/7.19+.....+1/252.509
giải jup mình với
Tính A:
\(\frac{1}{2.9}+\frac{1}{9.7}+\frac{1}{7.19}+...+\frac{1}{252.509}\)
Tính
a) A= 1/2.9 + 1/9.7 + 1/7.19 +....+ 1/252.509
b) B= 1/10.9 + 1/18.13 + 1/26.17+.... + 1/802.405
Nhanh nhaaa iuuu
tính \(y=\frac{1}{2.9}+\frac{1}{9.7}+\frac{1}{7.19}+...+\frac{1}{252.509}\)
Tính :
a)A=1/2.9 + 1/9.7 + 1/7.19 + ...+1/252.509
b)B=1/10.9 + 1/18.13 + 1/26.17 + ... + 1/802.405
c)C=2/4.7 - 3/5.9 +2/7.10 - 3/9.13+...+2/301.304 - 3/401.405
tính nhanh :
A = \(\frac{1}{2.9}+\frac{1}{9.7}+\frac{1}{7.19}+......+\frac{1}{252.509}\)
B = \(\frac{1}{10.9}+\frac{1}{18.13}+\frac{1}{26.17}+......+\frac{1}{802.405}\)
chung minh A<1/10:A=1/2.9+1/9.7+..+1/252.509
Tính tổng:
1/2.9 +1/9.7+1/7.19+...+1/252.504
