Bonjour j'ai besoin de votre aide s’il vous plaît pour ces exercices de maths merci d’avence

Bonjour

28)

a. 5/11 x 2/5 = 10/55 = (5 x 2) / (5 x 11) = 2/11

b. 4/7 x 5/2 = 20/14 = (2 x 10) / (2 x 7) = 10/7

c. 7/3 x 6/5 = 42/15 = (3 x 14) / (3 x 5) = 14/5

29)

a. - 2/7 x 14/16 = - 28/112 = (28 x - 1)  /(28 x 4) = - 1/4

b. - 3/5 x - 15/7 = 45/35 = (5 x 9) / (5 x 7) = 9/7

c. - 4/3 x 3/5 = - 12/15 = (3 x - 4) / (3 x 5) = - 4/5.

33)

a. 5/7 x 1/3 x - 1/2 = 5/21 x - 1/2 = - 5/42

b. - 3/5 x - 1/2 x - 2/7 = 3/10 x - 2/7 = - 6/70 = (2 x - 3) / (2 x 35) = - 3/35.