bonjour
a) x/2 + 1/4 = x/8 + 5/8
4 x /8 + 2/8 = x/8 + 5/8
4 x/8 - x/8 = 5/8 - 2/8
3 x = 3
x = 1
b) 2 x /3 + 1/5 = x/5 - 1/3
10 x /15 + 3/15 = 3 x /15 - 5/15
10 x - 3 x = - 5 - 3
7 x = - 8
x = - 8/7
c) 5 x /7 - 2 = x/5 + 1/3
75 x /105 - 310/105 = 21 x /105 + 35/105
75 x - 21 x = 32 + 310
54 x = 342
x = 342/54 = 19/3
fais le dernier