How do you solve problems with two inequalities?

If your problem looks like this:  3  <  2x + 6  < 18

Get the variable term alone in the center section by doing the same thing to all three parts.

First, get rid of the 6, by subtracting 6 from all three parts:

                  3 - 6  <  2x + 6 - 6  <  18 - 6

                        -3  <  2x  <  12

Now, divide all three parts by 2:

                     -3 ÷ 2  <  2x ÷ 2  <  12 ÷ 2

                        -1.5  <  x  <  6

Umm...

Take this equation for ex: 1k-4<2k-4

1k-4<2k-6

1k-4+4<2k-6+4

1k<2k-2

1k+2<2k-2+2

1k+2<2k

1k+2-1k<2k-1k

2<k

 

I hope this helped... sorry i couldn't go in depth