Start from zero — the basic math you need before everything else
In algebra a term is a single piece of an expression, like 3x or 5 or 2x². Like terms share the exact same letter part. So 3x and 5x are like terms, but 3x and 5 are not.
You can combine like terms by adding their number parts (the coefficients): 3x + 5x = 8x. You cannot combine unlike terms, so 3x + 5 stays as it is. The distributive law lets you multiply into brackets: a(b + c) = ab + ac, so 2(x + 3) = 2x + 6.
Combining like terms is just sorting. You can add 3 apples and 5 apples to get 8 apples, but 3 apples and 5 oranges won't merge — different fruit. In algebra the 'fruit' is the letter: 3x + 5x = 8x, but 3x + 5 stays apart. Multiplying a bag of mixed fruit by 2 doubles each kind: 2(x + 3) = 2x + 6.
▶ Simplifying Expressions