Les exercice sont sur les photo merci j ai vraiment besoin d aide

Pour l'exercice 4 (derniere photo):

A= 5/12 + 13/12 = 18/12 (Simplification: 18:2/12:2 = 9/6 )
B= 16/3-3 = 16/3 - (3/3 * 3) = 16/3 - 9/3 = 7/3
I= 6/7 + 8/14 = (6*2/7*2) + 8/14 = 12/14 + 8/14 = 20/14 (Simplification: 20:2/14:2 = 10/7)
D= 15/8 - (1/4 + 1/8) = 15/8 - (1*2/4*2 - 1/8) = 15/8 - (2/8 + 1/8) = 15/8 - 3/8 = 12/8 (Simplification: 12:4/8:4 = 3/2
E= 1/4 + 3/4 x 3 = 1/4 + 9/4 = 10/4 (Simplification:10:2/4:2 = 5/2 )
J= 5/6 - 5/24 = 5x4/6x4 -5/24 = 20/24 - 5/24 = 15/24 (Simplification:15:3/24:3 = 5/8.
J'espere que je t'ai aidé!! ;)