Respuesta :

the answer to this is

x=9,-15

Answer:

x={9,-15}

Step-by-step explanation:

|x+3|=12 means

x+3 could be 12 or -12 since |12|=12 and |-12|=12 are true

x+3=12                              x+3=-12

x=12-3                               x=-12-3

x=9                                    x=-15