Pre-Algebra
Combining Like Terms
Lesson
Like terms are terms that have the exact same variable part. and are like terms. and are not — one has an and one doesn’t.
To combine like terms, add or subtract their coefficients (the numbers in front). The variable part stays the same.
- Plain numbers (constants) are like terms with each other.
- A variable with no number means its coefficient is — so means .
- Pay attention to the sign in front of each term — it travels with the term.
Worked example 1
Group the like terms: the -terms together, constants alone:
Combine the coefficients of the -terms:
Worked example 2
Group -terms and constants:
Remember means , so :
How to type your answer
Write the variable term first, then the constant. No spaces needed. Use a for and -a for . Examples: 8x, 6a+6, -5y+10.
Practice
Work through these. Stuck? Click Get a hint.
Warm-Up
Quick problems to get going.
Problem 1
Problem 2
Problem 3
Problem 4
Practice
Standard problems matching the lesson.
Problem 5
Problem 6
Problem 7
Problem 8
Problem 9
Problem 10
Problem 11
Problem 12
Problem 13
Problem 14
Challenge
Harder problems — edge cases, trickier numbers, multiple steps.
Problem 15
Problem 16
Problem 17
Problem 18
Problem 19
Problem 20