Voici l’exercice en photo,merci à vous

Bonjour

A = 7/3 - 4/3 / 8/5

= 3/3 / 8/5

= 1 × 5/8

  = 5/8

B = -4/9 × 1/5 / 3/7

  = -4×1/9×5 / 3/7

  = -4/45 / 3/7

  = -4/45 × 7/3

  = -4×7 / 45×3

  = -28/135

C = -8/3 / -5/6 + 7/4

   = -8/3 × -6/5 + 7/4

   = (-8)×(-6) / 3×5

   = (-8)×(-2)×3 / 3×5

   = 16/5

D = -7/5 / (2/9 - 7/18)

   = -7/5  / (2×2/9×2 - 7/18

   = -7/5 / (4/18 - 7/18)

   = -7/5 / (-3/18)

   = -7/5 / (-1×3/6×3)

   = -7/5 / (-1/6)

   = -7/5 × (-6/1)

   = -7×-6 / 5×1

   = 42/5

E = (4/5 + -3/2) / (-9/4 - 1/6)

  = (4×2/5×2 + -3×5/2×5) / (-9×3/4×3 - 1×2/6×2)

  = (8/10 -15/10) / (-18/12 - 2/12)

  = (-7/10) / (-20/12)

  = (-7/10) × (-12/20)

  = -7×-12 / 10×20

  = 84/200

  = 21/50