Bonsoir;

exercice 1

A= 7/3 -4/3*5/8

= 7/3 -20/24

= 56/24-20/24

=36/24

= 18/12 = 9/6 = 3/2

B= -4/3 +14/30

= -40/30 +14/30

= -26/30

= -13/15

C= (-13/15 -6/15) * ( -3/18 +4/18)

=-19/15 * 1/18

= -19/ 270