Các câu hỏi tương tự
Tính bằng cách thuận tiện
1,\(\frac{13}{19}\left(\frac{19}{26}-\frac{71}{43}\right)+\frac{71}{43}\left(\frac{13}{19}-\frac{86}{71}\right)\)
2,\(\frac{5}{7}\left(\frac{1}{2}-\frac{1}{3}+\frac{4}{7}\right)+\left(\frac{1}{2}-\frac{1}{3}-\frac{4}{7}\right):\frac{7}{5}\)
B=\(\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+...+\frac{1}{1+2+3+...+10}\)
C=\(\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}+\frac{89}{90}\)
tinh:
\(\frac{\frac{4}{5}-\frac{4}{71}+\frac{4}{123}}{\frac{3}{5}-\frac{3}{71}+\frac{3}{123}}\)-\(\frac{\frac{1}{19}+\frac{1}{1315}-\frac{1}{287}}{\frac{3}{19}+\frac{3}{1315}-\frac{3}{287}}\)
RÚT GỌNAfrac{12+frac{12}{7}-frac{12}{25}-frac{12}{71}}{4+frac{4}{7}-frac{4}{25}-frac{4}{71}}:frac{3+frac{3}{13}+frac{3}{15}+frac{3}{15}+frac{3}{101}}{5+frac{5}{13}+frac{5}{15}+frac{5}{101}}Bfrac{frac{1}{51}+frac{1}{52}+frac{1}{53}+......+frac{1}{100}}{frac{1}{1.2}+frac{1}{3.4}+frac{1}{5.6}+.......+frac{1}{99.100}}
Đọc tiếp
RÚT GỌN
\(A=\frac{12+\frac{12}{7}-\frac{12}{25}-\frac{12}{71}}{4+\frac{4}{7}-\frac{4}{25}-\frac{4}{71}}:\)\(\frac{3+\frac{3}{13}+\frac{3}{15}+\frac{3}{15}+\frac{3}{101}}{5+\frac{5}{13}+\frac{5}{15}+\frac{5}{101}}\)
\(B=\frac{\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+......+\frac{1}{100}}{\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.......+\frac{1}{99.100}}\)
Chứng minh rằng số tự nhiên \(A=1\times2\times3\times...\times69\times70\times\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{70}\right)⋮71\)
26 tháng 6 2016 lúc 18:37
Tính :
\(A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right).....\left(1-\frac{1}{100}\right)\)
\(B=\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}\)
\(A=\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}+\frac{89}{90}\)
\(A=\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}+\frac{89}{90}\)
Tính \(A=\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}+\frac{55}{56}+\frac{71}{72}+\frac{89}{90}\)