Répondre :
A) 8/5 - x = 1
-x=1-8/5
-x=5/5-8/5
-x=-3/5
x=3/5
b) x + 8/3 = 31/6
x=31/6-8/3
x=31/6-16/6
x=15/6
x=5/2
c) x - 2/3=31/12
x=31/12+2/3
x=31/12+8/12
x=39/12
x=13/4
-x=1-8/5
-x=5/5-8/5
-x=-3/5
x=3/5
b) x + 8/3 = 31/6
x=31/6-8/3
x=31/6-16/6
x=15/6
x=5/2
c) x - 2/3=31/12
x=31/12+2/3
x=31/12+8/12
x=39/12
x=13/4