Répondre :
a) 3/7 + x = 2
x = 2 - 3/7
x = 14/7 - 3/7
x = 11/7
b) 1/2 + 1/4 + 1/6 + x = 1
12/24 + 6/24 + 4/24 + x = 1
22/24 + x = 1
x = 1 - 22/24
x = 24/24 - 22/24
x = 2/24 = 1/12
c) -3/5 + x = 4/15
x = 4/15 + 3/5
x = 4/15 + 9/15
x = 13/15
x = 2 - 3/7
x = 14/7 - 3/7
x = 11/7
b) 1/2 + 1/4 + 1/6 + x = 1
12/24 + 6/24 + 4/24 + x = 1
22/24 + x = 1
x = 1 - 22/24
x = 24/24 - 22/24
x = 2/24 = 1/12
c) -3/5 + x = 4/15
x = 4/15 + 3/5
x = 4/15 + 9/15
x = 13/15