Exercices 1 je n'y arrive pas aidez vous pour demain enfin lundi !!!

a =5/4 -(1/8 +3/8 x 2) +1/2
a = 5/4 - ( 1/8 +6/8) +1/2
a = 5/4 - 7/8 +1/2
a = 10/8 -7/8 +4/8
a = 14/8-7/8
a = 7/8

b = 3 / 1+7/5
b=  3 / 5/5+7/5
b = 3 /12/5
b = 3 x 5/12
b = 15/12
b = 5/4