Negative Terms
Part of the Expressions & Data section of Coddy's Pre-Algebra journey. Lesson 18 of 52.
Combining like terms is integer arithmetic on the numbers in front of the letter. 2k - 9k: 2 - 9 is -7, so the result is -7k. Taking away more k's than you have leaves a negative number of them, just as 2 - 9 is below zero.
The rules from Section 1 apply unchanged. -x - 4x is -5x, since -1 - 4 is -5. And -6k + 6k is 0k, which is 0: the terms cancel.
A full example: 2k - 9k + 4. The k terms give -7k and the number 4 stays alone, so the result is -7k + 4. A negative first term is perfectly simple; there is no need to rearrange it.
Challenge
Simplify 3y - 7y + 2 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