Aider moi a faire mon exercice svp​

bonjour,

exercice 1:

= 19/4 - [1/2-(3/8-1/4)

= 19/4 - [1/2-(3/8-2/8)

= 19/4 - [1/2-1/8]

= 19/4 - [4/8-1/8]

= 19/4 - 3/8

= 38/8 - 3/8

= 35/8

exercice 2:

a= 3

b= 5

c= -7

A= 1/a + 2/b - 3/c

A= 1/3 + 2/5 - 3/-7

A= 5/15 + 6/15 - 3/-7

A= 11/15 - 3/-7

A= 77/105 - 45/-105

A= 77/105 + 45/105

A= 122/105

B= b/a + a/b

B= 5/3 + 3/5

B= 25/15 + 9/15

B= 34/15

bonne journée :)