What are like terms how can u combine them?

Like terms are terms that have the same variable degree.

For example, 3x and 10x are like terms because they both have x^1

2 and 4 are also like terms because they both have x^0

Like terms have the same variable at the end. For example, 2x and 3x where x is the common variable. You can do order of operations with like terms.