bjr
|a| = 4/3 signifie a = -4/3 ou a = 4/3
1)
|x - 2| = 4/3 <=> x - 2 = -4/3 ou x - 2 = 4/3
x = 2 - 4/3 ou x = 2 + 4/3
x = 6/3 - 4/3 ou x = 6/3 + 4/3
x = 2/3 ou x = 10 /3
S = {2/3 ; 12/3}
2)
|a| < 4 signifie -4 < a < 4
|x + 1| < 4 <=> -4 < x + 1 < 4 (on ajoute -1)
-4 - 1 < x + 1 - 1 < 4 - 1
-5 < x < 3
S = ]-5 ; 3[