☺ Salut ☺
[tex]\\[/tex]
[tex]\rule{6cm}{1mm}[/tex]
1. Écrivons sous forme de fraction irréductible :
[tex]A = (\dfrac{4}{5} - 2) \div (2 - \dfrac{11}{14})[/tex]
[tex]A = (\dfrac{4 - 10}{5} ) \div ( \dfrac{28 - 11}{14})[/tex]
[tex]A = - \dfrac{6}{5} \div \dfrac{17}{14}[/tex]
[tex]A = - \dfrac{6}{5} \times \dfrac{14}{17}[/tex]
[tex]\boxed{\boxed{\red{A = - \dfrac{84}{85}}}}[/tex]
[tex]B = \dfrac{45}{28}\times\dfrac{12}{63}[/tex]
[tex]B = \dfrac{540}{1764} [/tex]
[tex]B = \dfrac{45}{147} [/tex]
[tex]\boxed{\boxed{\pink{B = \dfrac{15}{49} }}}[/tex]
2. Donnons l'écriture scientifique :
[tex]C = \dfrac{2.5\times{10}^{3}\times{10}^{- 5}}{50\times{10}^{- 2}}[/tex]
[tex]C = \dfrac{2.5\times{10}^{- 2}}{50\times{10}^{- 2}}[/tex]
[tex]C = 0,05[/tex]
[tex]\boxed{\boxed{\green{C = 5\times{10}^{- 2}}}}[/tex]
[tex]\rule{6cm}{1mm}[/tex]
