Ta có:
\(A=\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+...+\frac{5^2}{26.31}\)
\(A=5\left(\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{26.31}\right)\)
\(A=5\left(\frac{1}{1}-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+...+\frac{1}{26}-\frac{1}{31}\right)\)
\(A=5\left(\frac{1}{1}-\frac{1}{31}\right)\)
\(A=5.\frac{30}{31}\)
\(A=\frac{150}{31}\)
Vậy \(A=\frac{150}{31}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\) =?
Tinh
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)
Tính tổng trên bằng cách hợp lí
\(\frac{3}{5}va\frac{3+m}{5+m}\) Hãy so sánh 2 số trên
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\) Tính tổng
\(\frac{5^2}{1.6}\)+ \(\frac{5^2}{6.11}\)+ \(\frac{5^2}{11.16}\)+ \(\frac{5^2}{16.21}\)+ \(\frac{5^2}{21.26}\)+ \(\frac{5^2}{26.31}\)= ?
(x+3).(2y-1)=9
S=\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}\)
CÁC BẠN ƯI, GIÚP MIK MẤY BÀI NÀY NHA
\(\frac{\frac{3}{41}-\frac{12}{47}+\frac{27}{53}}{\frac{4}{41}-\frac{16}{47}+\frac{36}{53}}=?\)\(4+2^2+2^4+...+2^{20}\)\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{^{5^2}}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}\)Đây là câu trả lời của Đinh Nguyễn Nguyệt Hà
\(A=\frac{5.2}{1.6}+\frac{5.2}{6.11}+\frac{5.2}{11.16}+\frac{5.2}{16.21}+\frac{5.2}{21.26}+\frac{5.2}{26.31}\)
\(\frac{A}{2}=\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+\frac{5}{16.21}+\frac{5}{21.26}+\frac{5}{26.31}\)
\(=1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}+\frac{1}{21}-\frac{1}{26}+\frac{1}{26}-\frac{1}{31}\)
\(=1-\frac{1}{31}=\frac{30}{31}\)
\(\Rightarrow A=\frac{30}{31}.2=\frac{60}{31}\)
Nếu tử là 52 thì cậu chuyển thành 5.5 rồi chuyển 5 sang vế trái thành A/5 nha, cũng giống như trên thui!!!!!!!!
Tính tổng :
\(\frac{5^2}{1.6}\)+\(\frac{5^2}{6.11}\)+\(\frac{5^2}{11.16}\)+\(\frac{5^2}{16.21}\)+\(\frac{5^2}{21.16}\)+\(\frac{5^2}{26.31}\)
