Question 1170672
<pre>
Rewrite

{{{-3 <= x <=-1}}}

-----------&#x2B24;====&#x2B24;----------
-6  -5 -4 -3 -2 -1  0  1  2
Find the midpoint between the endpoints by looking and seeing
that -2 is right in the middle, or else by averaging them:

{{{((-3)+(-1))/2=(-4)/2=-2}}}

We see that the midpoint is each exactly 1 unit from each
endpoint.  So the absolute value of the difference between any
point on the interval and the midpoint is 1 unit, so the way
to say that is

{{{abs(x-(-2))<=1}}}

or simplifying

{{{abs(x+2)<=1}}}

Edwin</pre>