3 * | x + 3 | = 48
| x + 3 | = 16
x + 3 = 16
x + 3 = -16
x  = 13

x = -19

x₁ = -19

x₂ = 13

Ответ:

3 |х + 3| = 48

|х + 3| = 16

х + 3 = 16

х + 3 = - 16

х = 13

х = - 19

х1 = - 19, х2 = 13