case (i)
-1<x<1
x^2-1 <0: |x^2-1| = -(x^2-1)
therefore -x^2+1+x+1=0
-x^2+x+2=0
by solving the equation
we get x= 2, -1
as this is outside our limit (-1<x<1)
they are not the solution
case(ii)
x=or >1 or x < or = -1
therefore x^2-1>0 : |x^2-1| = x^2-1
x^2-1+x+1=0
x^2+x =0
x(x+1) =0
therefore x= 0 , -1
0 is not an answer as it is outside the limit
so solutuion for the given quation is -1