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