Coucou!
1) (de gauche à droite)
x = -1
-15x = 21
x + 6 = 10
-6x = -24
-2 - x = 2
-6x = -10
X = 7/3
-2x = -54
-7/5 = x
3x = -24
2)
x = 6 ; *3 ; 3x = 18
x = 7 ; *5 ; 5x = 35
x = -5 ; + 8 ; x + 8 = 3
x = -8 ; - 9 ; x - 9 = -17
x = 7 ; *(-2) ; -2x = -14
x = 6 ; *(-7) ; -7x = -42
-5 = x ; *(-5) ; -5x = 25
-2x = 3 ; *(-3) = -9
x = 7 ; *(-8) ; -8x = 56
