Question

|x+1|+|-x-1|=0 .....​

Answer 1

$\it |-x-1|=|-(x+1)|=|x+1|$

Ecuația  devine:

$\it |x+1|+|x+1|=0 \Rightarrow 2|x+1|=0 \Rightarrow |x+1|=0 \Rightarrow x+1=0 \Rightarrow x=-1$