Bonjour pouvez-vous m'aider pour les 3 exercices merci

Bonjour,

17)

A = 5 x 2/3

A = 10/3

B = - 7/5 x 4

B = - 28/5

C = 5/6 x - 11/4

C = - 55/24

D = - 8/9 x - 10/9

D = 80/81

18)

A = 8/7 x 2/9 = 16/63

B = - 5 x 4/9 = - 20/9

19)

A = - 5/9 x - 2/17

A = 10/153

B = 3/- 9 x - 2/- 5

B = - 6/45

B = (3 x - 2) / (3 x 15)

B = - 2/15

C = - - 4/5 x - 3/25

C = - 12/125

D = - 1/- 7 x - 2/- 5

D = 2/35.