Like Terms
Part of the Expressions & Data section of Coddy's Pre-Algebra journey. Lesson 16 of 52.
2x + 4x is two x's plus four x's, which makes six x's: 6x. Terms with the same letter, raised to the same power, are called like terms, and they can be added into one term by adding their numbers.
Why does this work? It is the distributive property read backwards: 2x + 4x is (2 + 4)x, which is 6x. A letter on its own has the number 1 in front of it, so 7a + a is 8a.
Unlike terms stay apart. 3x + 5 cannot become 8x, because 5 is not a number of x's; and 3x + 2y stays as it is, since x and y can be different numbers. Three apples and five pears make eight pieces of fruit, but never eight apples.
Challenge
Combine the like terms in 5x + 3x and type the result as your next line.
Try it yourself
Simplify the expression
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Expressions & Data
1Variables and Expressions
What a Variable IsWriting ExpressionsExpressions from StoriesTwo OperationsRecap: Expressions4Combining Like Terms
Like TermsLetters and NumbersNegative TermsTwo LettersDistribute, Then CollectRecap: Like Terms2Evaluating Expressions
Substituting a ValueNegative InputsPowers in ExpressionsFormulasRecap: Evaluating5Patterns and Sequences
Continuing a PatternThe Common DifferenceThe nth TermWriting the RuleRecap: Sequences3The Distributive Property
Number PropertiesMental MathDistributing LettersDistributing a MinusRecap: Distributing