Bonsoir,
[tex]A = \dfrac{6}{7}-\dfrac{4}{7}\times \dfrac{5}{2}\\\\
= \dfrac{6}{7}-\dfrac{20}{14}\\\\
= \dfrac{6}{7}-\dfrac{10}{7}\\\\
= -\dfrac{4}{7}\\\\[/tex]
[tex]B = \dfrac{2}{3}-\dfrac{3}{2}\times \dfrac{4}{9}+\dfrac{1}{2}\\\\
= \dfrac{2}{3}-3\times\dfrac{2}{9}+\dfrac{1}{2}\\\\
= \dfrac{2}{3}-\times\dfrac{2}{3}+\dfrac{1}{2}\\\\
= \dfrac{1}{2}[/tex]
[tex]C = \dfrac{2}{5}\times \left(3-\dfrac{9}{7}\right)\\\\
= \dfrac{2}{5}\times \dfrac{21-9}{7}\\\\
= \dfrac{2}{5}\times \dfrac{12}{7}\\\\
= \dfrac{24}{35}[/tex]
[tex]D = \left(\dfrac{1}{2}-\dfrac{1}{3} \right )\left(\dfrac{3}{4}+\dfrac{4}{5} \right )\\\\
= \dfrac{3-2}{6}\times\dfrac{15+16}{20}\\\\
= \dfrac{1}{6}\times \dfrac{31}{20}\\\\
= \dfrac{31}{120}[/tex]
[tex]E = \dfrac{3}{4}-\left(\dfrac{-5}{12}-\dfrac{1}{3} \right )\times\dfrac{18}{-36}\\\\
= \dfrac{3}{4}-\left(\dfrac{-5-4}{12}\right )\times\dfrac{18}{-36}\\\\
= \dfrac{3}{4}+\dfrac{9}{12}\times\dfrac{18}{-36}\\\\
= \dfrac{3}{4}+\dfrac{3}{4}\times\dfrac{18}{-36}\\\\
= \dfrac{3}{4}-\dfrac{3}{4}\times\dfrac{1}{2}\\\\
= \dfrac{3}{4}-\dfrac{3}{8}\\\\
= \dfrac{6-3}{8}\\
= \dfrac{3}{8}[/tex]
Bonne soirée.
