Unlike Terms

The unlike terms are x an x^2 because they have different exponents. You can combine terms that have the same exponent but if they don't have the same exponent, they are unlike terms and u can't combine unlike terms. Something you can remember is if they don't have the same variable don't combine anything. You can not multiply  8m*2m because that makes it one term because  multiplication or division dose not separated  and term. An coefficient is the number in an expression. The coefficient is important because it tell you how many of the variable you have.