It's better to swap them so the numbers will go from smallest
to largest,
Draw the number line graph:
<============☻-----------☺=============================>
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9
Interval notation is just an abbreviation for the graph on a
number line.
If the graph goes all the way to the left, put
on the left end of the
interval notation
If the graph goes all the way to the right, put
on the right end
of the interval notation
Edwin
