Réponse:
[tex]a = 3 - \frac{15}{9} \div \frac{5}{12} \\ = 3 - \frac{3 \times 5}{3 \times 3} \times \frac{3 \times 4}{5} \\ = 3 - \frac{3}{3} \times 4 \\ = 3 - 1 \times 4 \\ = 3 - 4 \\ a= - 1[/tex]
[tex]b = \frac{3 - \frac{2}{3} }{ \frac{4}{3} \times 7 } \\ = \frac{ \frac{3 \times 3 - 2}{3} }{ \frac{4 \times 7 \times 3}{3} } \\ = \frac{ \frac{9 - 2}{3} }{ \frac{4 \times 7 \times 3}{3} } \\ = \frac{7}{3} \times \frac{3}{4 \times 7 \times 3 } \\ b = \frac{1}{4 \times 3} = \frac{1}{12} [/tex]
[tex]c = 4 - \frac{3}{4} \times ( \frac{1}{3} - \frac{1}{6} ) \\ = 4 - \frac{3}{4} \times ( \frac{2 - 1}{6} ) \\ = 4 - \frac{3}{4} \times ( \frac{1}{6} ) \\ = 4 - \frac{3 \times 1}{4 \times 6} \\ = 4 - \frac{3}{24} \\ = \frac{4 \times 24- 3}{24} \\ = \frac{96 - 3}{24} \\ c= \frac{93}{24} [/tex]
