calculer en donnant le résultat sous la forme d'une fraction aidez moi svppppp​

Bonjour

A = 1/5 + 7/20

A = (1 x 4) / (5 x 4) + 7/20

A = 4/20 + 7/20

A = 11/20

B = 7/6 + 2/30

B = (7x 5) / (6 x 5) + 2/30

B = 35/30 + 2/30

B = 37/30

C = - 2/3 + 7/33

C = (- 2 x 11) / (3 x 11) + 7/33

C = - 22/33 + 7/33

C = - 15/33

C = (3 x - 5) / (3 x 11)

C = - 5/11.

D = 7/12 + 5/4

D = 7/12 + (5 x 3) / (4 x 3)

D = 7/12 + 15/12

D = 22/12

D = (2 x 11) / (2 x 6)

D = 11/6

E = - 7/40 + 3/4

E = - 7/40 + (3x 10) / (4 x 10)

E = - 7/40 + 30/40

E = 23/40

F = 9/28 + 3/4

F = 9/28 + (3 x 7) / (4 x 7)

F = 9/28 + 21/28

D = 30/28

D = (2 x 15) / (2 x 14)

D = 15/14.