tính nhanh
Q=\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+.......+\frac{5^2}{26.31}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\) =?
Tinh
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
(x+3).(2y-1)=9
S=\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}\)
\(C=\frac{5^2}{1.6}.\frac{5^2}{6.11}...\frac{5^2}{2010.2015}\)=?
tính
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+...+\frac{5^2}{26.30}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
Tính tổng trên bằng cách hợp lí
Tính B , biết :
\(B=\frac{5^2}{1.6}+\frac{5^2}{6.11}+.....+\frac{5^2}{26.31}\)
