C=\(\frac{1}{3}+\frac{1}{10}+\frac{1}{15}+\frac{1}{20}+\frac{1}{25}+\frac{1}{30}+\frac{1}{35}+\frac{1}{40}\)
=\(\frac{1}{3}+\frac{1}{15}+\frac{1}{10}+\frac{1}{20}+\frac{1}{30}+\frac{1}{40}+\frac{1}{25}+\frac{1}{35}\)
=\(\frac{5}{15}+\frac{1}{15}+\frac{4}{40}+\frac{2}{40}+\frac{1}{40}+\frac{1}{30}+\frac{1}{25}+\frac{1}{35}\)
=\(\frac{6}{15}+\frac{7}{40}+\frac{107}{1050}\)
tính nhanh \(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{1}{45}+\frac{1}{55}\)
Tính nhanh:\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{1}{45}\)
tính nhanh:
C= \(\frac{1}{3}\)+\(\frac{1}{10}\)+\(\frac{1}{15}\)+....................+\(\frac{1}{45}\)
Tính
\(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{2004\times2005}+\frac{1}{2005\times2006}=A\)
\(\frac{1}{6}+\frac{2}{15}+\frac{4}{45}+\frac{2}{99}+\frac{10}{600}=A\)
các bạn giải chi tiết giúp mình.Tính nhanh: \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+....+\frac{1}{45}\)
tính nhanh:\(\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+.....+\frac{1}{195}\)
Tính nhanh : \(\frac{4}{3}+\frac{7}{6}+\frac{11}{10}+\frac{16}{15}+\frac{22}{21}+\frac{29}{28}+\frac{37}{36}+\frac{46}{45}\)
bài 1 : tính phân số:
a) \(\frac{5}{7}+\frac{4}{9}=?;\frac{4}{5}-\frac{2}{3}=?;\frac{9}{11}+\frac{3}{8}=?;\frac{16}{25}-\frac{2}{5}=?\)=?
b)\(5+\frac{3}{5}=?;10-\frac{9}{16}=?;\frac{2}{3}-\left(\frac{1}{6}+\frac{1}{8}\right)=?\)
c)\(\frac{5}{7}+\frac{7}{6}=?;\frac{7}{12}+\frac{17}{18}=?;\frac{9}{8}+\frac{15}{32}=?;4+\frac{35}{45}=?\)
d)\(\frac{11}{4}-\frac{15}{16}=?;\frac{5}{6}-\frac{5}{8}=?;\frac{196}{64}-2=?;3-\frac{13}{9}=?\)
e)\(\frac{8}{5}+\frac{7}{6}+\frac{5}{9}-2=?;3-\frac{5}{6}-\frac{4}{9}+\frac{32}{24}=?\)
Hướng dẫn tôi cách tính nhanh phân số sau
\(A=\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}\)
