Câu 1:
a)\(\frac{5}{7}.\frac{14}{17}+\frac{1}{17}.\frac{5}{9}+\frac{2}{9}.\frac{5}{17}\)
\(=\frac{5}{7}.\frac{14}{17}+\frac{5}{7}.\frac{7}{85}.\frac{5}{9}+\frac{5}{7}.\frac{7}{17}.\frac{2}{9}\)
\(=\frac{5}{7}.\frac{14}{17}+\frac{5}{7}.\frac{7}{153}+\frac{5}{7}.\frac{14}{153}\)
\(=\frac{5}{7}.\left(\frac{14}{17}+\frac{7}{153}+\frac{14}{153}\right)\)
\(=\frac{5}{7}.\frac{49}{51}\)
\(=\frac{35}{51}\)
b)\(4,8.\frac{15}{24}-\left(\frac{4}{5}+\frac{9}{3}\right):3\frac{2}{3}\)
\(=3-\frac{19}{5}:3\frac{2}{3}\)
\(=3-\frac{57}{55}\)
\(=\frac{171}{55}\)
c)\(1\frac{13}{15}.0,75-\left(\frac{104}{195}+25\%\right).\frac{24}{47}-3\frac{13}{12}\)
\(=1,4-\frac{1532}{15}.\frac{24}{47}-3\frac{13}{12}\)
\(=1,4-\frac{12256}{235}-3\frac{13}{12}\)
=\(\frac{-11927}{235}-3\frac{13}{12}\)
d)\(\frac{\frac{2}{3}+\frac{2}{5}-\frac{2}{9}}{\frac{4}{3}+\frac{4}{5}-\frac{4}{9}}\)
\(=\frac{\frac{2}{3}+\frac{2}{5}-\frac{2}{9}}{2.\left(\frac{2}{3}+\frac{2}{5}-\frac{2}{9}\right)}\)
\(=\frac{1}{2}\)
