=\(\frac{-20}{21}.\left(\frac{22}{35}+\frac{13}{35}\right)+\frac{-22}{21}\)
=\(\frac{-20}{21}.\left(\frac{35}{35}\right)+\frac{-22}{21}\)
=\(\frac{-20}{21}+\frac{-22}{21}\)
=\(\frac{-42}{21}\)=-2
\(\frac{1}{20}+\frac{1}{21}+\frac{1}{22}+...+\frac{1}{49}<\frac{13}{12}\)
C/m ::
\(S=\frac{1}{12}+\frac{1}{13}+\frac{1}{14}+\frac{1}{15}+\frac{1}{16}+\frac{1}{17}+\frac{1}{18}+\frac{1}{19}+\frac{1}{20}+\frac{1}{21}+\frac{1}{22}>\frac{1}{2}\)
\(A=\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+...+\frac{13}{53}\)\(B=\frac{16}{15}+\frac{36}{35}+\frac{63}{63}+...+\frac{10000}{9999}\)
\(Giải-giúp-mk-nha\)
a) \(\frac{13}{36}\)+\(\frac{17}{45}\)+\(\frac{-23}{20}\)
b)\(\frac{18}{35}\)+\(\frac{-11}{21}\)+\(\frac{-23}{20}\)
TÍNH
Cho \(S=\frac{5}{20}+\frac{5}{21}+\frac{5}{22}+...+\frac{5}{49}\).CMR: 3<S<8
\(\frac{13}{21}\)+\(\frac{8}{21}\):\(\frac{16}{21}\) = ?
\(\frac{36}{35}\):\(\frac{8}{3}\)-\(\frac{36}{35}\):\(\frac{6}{11}\)= ?
Cho A=\(\frac{1}{20}+\frac{1}{21}+\frac{1}{22}+...+\frac{1}{58}+\frac{1}{59}.Chứngtỏ\)rằng A<\(\frac{3}{2}\)
Cho S =\(\frac{5}{20}+\frac{5}{21}+\frac{5}{22}+...+\frac{5}{49}\). Chứng minh : 3<S<8
cho A = \(\frac{1}{20}+\frac{1}{21}+\frac{1}{22}+...+\frac{1}{58}+\frac{1}{59}\)chứng minh A <\(\frac{3}{2}\)
