Réponse :
a) [tex]\frac{2}{7} * ( \frac{10}{21} * \frac{7}{2} ) = \frac{2}{7} * ( \frac{5}{3} * \frac{1}{1}) = \frac{2}{7} * \frac{5}{3} = \frac{10}{21}[/tex]
b) [tex]\frac{8}{3} * (\frac{64}{27} * \frac{3}{(8}) = \frac{8}{3} * ( \frac{8}{9} * \frac{1}{1} ) = \frac{8}{3} * \frac{8}{9} = \frac{64}{27}[/tex]
c) [tex]\frac{3}{7}*(\frac{2}{49}*\frac{7}{3})= \frac{3}{7} * (\frac{2}{7}* \frac{1}{3}) = \frac{3}{7}* \frac{2}{21} = \frac{1}{7}*\frac{2}{7}=\frac{2}{49}[/tex]
d) [tex]\frac{7}{2}*(\frac{-63}{4} * \frac{2}{7}) = \frac{7}{2} * (\frac{-9}{2}*\frac{1}{1}) = \frac{7}{2}*\frac{-9}{2}= \frac{-63}{4}[/tex]
e) [tex]\frac{-13}{4}*(\frac{26}{15}* \frac{-4}{13}) = \frac{-13}{4}*(\frac{2}{15}*\frac{-4}{1}) = \frac{-13}{4}*\frac{-8}{15}= \frac{-13}{1}*\frac{2}{15}=\frac{-26}{15}[/tex]
f)[tex]\frac{-9}{15} *(\frac{-72}{25}*\frac{-5}{9}) = \frac{-9}{15}*(\frac{-8}5}*\frac{1}{9}) = \frac{-9}{15}*\frac{-8}{45}= \frac{-1}{15}*\frac{-8}{5}= \frac{8}{75}[/tex]
g) [tex]5*(\frac{7}{4}*\frac{1}{5}) = 5*(\frac{7}{20}) = \frac{35}{20}= \frac{7}{4}[/tex]
h) [tex]-9*(\frac{42}{5}*\frac{1}{-9}) = 9*(\frac{42}{-45}) = 9* (\frac{14}{15}) = 3*\frac{14}{5}= \frac{42}{5}[/tex]
i) [tex]\frac{10}{3}*(-15*\frac{3}{10}) = \frac{10}{3} * (-3* \frac{3}{2}) = \frac{10}{3}*\frac{-9}{2}= \frac{5}{1}*\frac{-3}{1}= \frac{-15}{1} = -15[/tex]
