What about the inequality sign like < = >

The < and > signs mean lesser and greater than. = means equal(s). The signs will always look like they are eating the bigger value. For example:
12<29
Twelve is lesser than twenty-nine, or
29>12
Twenty-nine is greater than twelve.
An equation uses an equal sign
12+8=20
When you're using all of them, it can look like this:
1<n<29
This is read as "one is lesser than n which is lesser than 29". These can be used to determine the lengths of the sides of a triangle. In this case, n must be between 1 and 29 for it to be the side of a triangle.

The answer would be quadratic trinomial