Inequalities are very much like linear equations but instead of an '=' sign they use the following signs:
You can solve them in exactly the same way you solve linear equations with one extra rule that it is very important to remember!
If you multiply or divide the terms in an inequality by a negative number the inequality sign swaps round.
So, < would change to > and so on.
Simple as that! Here's an example:
Solve 12x - 5 < 8x + 3
4x - 5 < 3 (Subtracted 8x from both sides)
4x < 8 (Added 5 to both sides)
x < 2 (Divided both sides by 4 which gives us the answer!)