bonsoir quelqu'un peut m'aider svp c'est l'exercice 14 il faut bien détailler les calculs merciii d'avance :)

Bonsoir !

Exercice 14 :

A = -2/21 × 14/5 - 8/5

= -2×14/21×5 - 8/5

= -2×2×7/3×7×5 - 8/5

= -2×2/3×5 - 8/5

= -4/15 - 8/5

= -4/15 - 8×3/5×3

= -4/15 - 24/15

= -28/15

B = 1/4 + 5/3 × -1/8

= 1/4 + 5×-1/3×8

= 1/4 + -5/24

= 1×6/4×6 + -5/24

= 6/24 + -5/24

= 1/24

C = 4/-3 + -7/6 × -2/5

= -4/3 + -7×-2/6×5

= -4/3 + -7×-2/2×3×5

= -4/3 + 14/30

= -4×5/3×5 + 7×2/15×2

= -20/15 + 7/15

= -13/15

D = (8/15 - 7/5) × (-1/6 + 2/9)

= (8/15 - 7×3/5×3) × (-1×3/6×3 + 2×2/9×2)

= (8/15 - 21/15) × (-3/18 + 4/18)

= -13/15 × 1/18

= -13×1/15×18

= -13/270