Répondre :
bonsoir
( 2 x + 9 ) + ( 4 x - 9 )
= 2 x + 9 + 4 x - 9
= 6 x
5 x - 4 = 3 x + 10
5 x - 3 x = 10 + 4
2 x = 14
x = 7
bonne soirée
bonsoir
( 2 x + 9 ) + ( 4 x - 9 )
= 2 x + 9 + 4 x - 9
= 6 x
5 x - 4 = 3 x + 10
5 x - 3 x = 10 + 4
2 x = 14
x = 7
bonne soirée