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