C=15/28x7/25x1/6 ? D=24/7 divisé (-12) ? E=5/4-3/2+7/2 ? F=2+7/9x1/2 ? G= H= 3/4-2/7x1/2 ? Merci d'avance !

Bonjour Jadedu35

C=15/28x7/25x1/6 ?

[tex]C=\dfrac{15}{28}\times\dfrac{7}{25}\times\dfrac{1}{6}\\\\C=\dfrac{3\times5}{4\times7}\times\dfrac{7}{5\times5}\times\dfrac{1}{6}\\\\C=\dfrac{5}{4\times7}\times\dfrac{7}{5\times5}\times\dfrac{1}{2}\\\\C=\dfrac{5}{4}\times\dfrac{1}{5\times5}\times\dfrac{1}{2}\\\\C=\dfrac{1}{4}\times\dfrac{1}{5}\times\dfrac{1}{2}\\\\\boxed{C=\dfrac{1}{40}}[/tex]

D=24/7 divisé (-12)

[tex]D=\dfrac{24}{7}:(-12)\\\\D=\dfrac{24}{7}\times(\dfrac{1}{-12})\\\\D=\dfrac{2\times12}{7}\times(\dfrac{1}{-12})\\\\D=\dfrac{2}{7}\times(\dfrac{1}{-1})\\\\\boxed{D=-\dfrac{2}{7}}[/tex]

E=5/4-3/2+7/2 ?

[tex]E=\dfrac{5}{4}-\dfrac{3}{2}+\dfrac{7}{2}\\\\E=\dfrac{5}{4}-\dfrac{6}{4}+\dfrac{14}{4} \\\\E=\dfrac{5-6+14}{4}\\\\\boxed{E=\dfrac{13}{4}}[/tex]

F=2+7/9x1/2 ?

[tex]F=2+\dfrac{7}{9}\times\dfrac{1}{2}\\\\F=2+\dfrac{7}{18}\\\\F=\dfrac{36}{18}+\dfrac{7}{18}\\\\\boxed{F=\dfrac{43}{18}}[/tex]

G= 

(il n'y a pas d'expression dans l'énoncé)

H= 3/4-2/7x1/2 ? 

[tex]H= \dfrac{3}{4}-\dfrac{2}{7}\times\dfrac{1}{2}\\\\H= \dfrac{3}{4}-\dfrac{1}{7}\times\dfrac{1}{1} \\\\H= \dfrac{3}{4}-\dfrac{1}{7}\\\\H= \dfrac{3\times7}{4\times7}-\dfrac{1\times4}{7\times4}\\\\H= \dfrac{21}{28}-\dfrac{4}{28}\\\\\boxed{H= \dfrac{17}{28}} [/tex]