bonjour j'aurais besoin d'aide si quelqu'un pourrait m'aider svp​

Bonsoir

3/9 + 5/2

= (3 x 2)/(9 x 2) + (5 x 9)/(2 x 9)

= 6/18 + 45/18

= 51/18

6/7 - 2/3

= (6 x 3)/(7 x 3) - (2 x 7)/(3 x 7)

= 18/21 - 14/18

= 4/21

7/4 - 9/5

= (7 x 5)/(4 x 5) - (9 x 4)/(5 x 4)

= 35/20 - 36/20

= -1/20

3/8 + 1/7

= (3 x 7)/(8 x 7) + (1 x 8)/(7 x 8)

= 21/56 + 8/56

= 29/56

-7/3 + (-1/4)

= (-7 x 4)/(3 x 4) - (1 x 3)/(4 x 3)

= -28/12 - 3/12

= -31/12

2/11 - 3/10

= (2 x 10)/(11 x 10) - (3 x 11)/(10 x 11)

= 20/110 - 33/110

= -13/110