How would you figure out this compound
inequality.
2x-4 < 6-7x < 3x+6
That means
2x - 4 < 6 - 7x AND 6 - 7x < 3x + 8
9x < 10 AND -10x < 2
x < 10/9 AND x > -1/5
which means that on the number line,
x is less than (to the left of) 10/9
on the number line AND greater than
(to the right of) -1/5 on the number line,
like this:
----------o=============o-----------
-1/5 10/9
This can be written
-1/5 < x < 10/9
or in interval notation as
(-1/5, 10/9)
Edwin
