3 < 1 - 2x < 5


Subtract 1 from all three sides:


        3 < 1 - 2x < 5
       -1  -1       -1
       ———————————————
        2 < 0 - 2x < 4

or
          2 < -2x < 4

Divide every term by -2, which reverses the inequality symbols:

          >  > 

          -1 > x > -2

Using the fact that A > B > C is equivalent to C < B < A, we may
write thst, if we prefer, as

          -2 < x < -1

That interval of x-values is represented by this graph:

   ---------o===o------------
   -4  -3  -2  -1   0   1   2    

Or by this interval notation:

           (-2, -1)

Edwin