Answer :

so the anwers are 3 and -5

lets find an equation that when you put 3 and -5 in for x then get the absolute value, you get the same number so 

|x+1|=4

subtitute 3 and -5 for x
so |3+1|   |4|=4=true
|-5+1|=4    |-4|=4 absolut value makes all things within positive so 4=4=true
|x+1|=4
subtitute 3 and -5 for x
so |3+1|   |4|=4=true
|-5+1|=4    |-4|=4 absolut value makes all things within positive so 4=4=true