Réponse :
Explications étape par étape :
[tex]A=\frac{\frac{3}{2} -\frac{1}{3} }{\frac{3}{4} +\frac{2}{3} } =\frac{\frac{3*3-1*2}{2*3} }{\frac{3*3+2*4}{3*4} } =\frac{\frac{9-2}{6} }{\frac{9+8}{12} } =\frac{\frac{7}{6} }{\frac{17}{12} } =\frac{7}{6}*\frac{12}{17} =\frac{7*6*2}{6*17} =\frac{7*2}{17} =\frac{14}{17}[/tex]
[tex]B=\frac{3-\frac{7}{5} }{1-\frac{9}{10} } =\frac{\frac{3*5-7}{5} }{\frac{1*10-9}{10} } =\frac{\frac{15-7}{5} }{\frac{10-9}{10} } =\frac{\frac{8}{5} }{\frac{1}{10} } =\frac{8}{5} *\frac{10}{1} =\frac{80}{5} =16[/tex]
[tex]C=\frac{7}{-8} +\frac{\frac{5}{6} }{4} -1=\frac{7}{-8} +\frac{5}{6} *\frac{1}{4} -1=\frac{7}{-8} +\frac{5}{24} -1=\frac{7*-3}{-8*-3} +\frac{5}{24} -\frac{24}{24} =\frac{-21+5-24}{24} =\frac{-40}{24}=\frac{-5*2*4}{3*2*4} =\frac{-5}{3}[/tex]
