What are “like terms”? why can we only add like terms?

"Like terms" are terms whose variables (and their exponents such as the 2 in x2) are the same. In other words, terms that are "like" each other

only like terms can be combined. We combine like terms to shorten and simplify algebraic expressions, so we can work with them more easily.

hopefully it help

We can only add like terms because it is like if you break a vase and you need to replace it before ur mom comes home they need to be exactly the same.