# Thread: Linear inequalities.

1. ## Linear inequalities.

i am trying to learn how to slove linear inequalities and im stuck!

In problems like 6 -4x < x +1 i know the text book tells me to use -x to both sides.

Ok.. this brings me to my question. when doing these im lost on which number to pick and subtract!! why not the 6 or the 1. please help.

When i sit down and get ready to work the problem.. im stuck at the first step at.. do i add and sub the 6 through out the problem or or 1 or -4x.. where do i start?

2. You want to get x on only one side. By subtracting x from both sides you isolate it although I would add 4x to both sides to avoid negative inequalities giving $6 < 5x+1$

3. it really doesn't matter which you do first

edit didn't see previous reply

4. how would that work with this. -9<-3z-3<6 where would i start here and why? thank you for your help.. really.

5. A "compound" inequality (someone feel free to suggest a better word) is the same as -9<-3z-3 and -3z-3<6. Add 3 to both sides to get z on it's own: $-6 < -3z < 9$

You can then divide by -3 but don't forget to change the direction of the inequalities