Summarize this article:
Last updated on September 26, 2025
In algebra, expressions consist of terms separated by addition or subtraction. A term can include numbers, variables, or both. Identifying like and unlike terms helps simplify and solve algebraic expressions.
Like terms are terms that have the same variables with the same exponents, but they can have different coefficients. For example:
3x2 and 5x2 are like terms because both have the variable x2.
2xy and −7xy are like terms because both have the variable xy.
Unlike terms are defined as terms with different variables, or the same variables with different exponents. For example:
4x and 4y are unlike terms because they have different variables.
3x2 and 3x are unlike terms because the terms have different exponents.
ab and a2b are unlike terms because they have different powers of a.
The variables and their powers decide whether two terms are like or unlike. Understanding the difference between them helps us simplify and solve algebraic expressions.
Feature |
Like terms |
Unlike terms |
Definition |
Terms that have the same variables raised to the same exponents. |
Terms that have different variables, or the same variables with different exponents. |
Example |
2x and 3x; 4xy and 5xy |
3x and 3y; 5x3 and 5x |
Can the terms combine? |
Yes, like terms can be added or subtracted. |
No, unlike terms cannot be combined directly. |
Simplification |
Can be easily simplified by combining coefficients. |
Cannot be simplified unless rewritten as like terms. |
Like terms can be added or subtracted easily by following these simple steps:
Step 1: Identify like terms—these are terms that have the same variables with the same exponents. Once identified, you can add or subtract their coefficients. For example, 2x + 3x = 5x.
Step 2: Add or subtract the coefficients of like terms while keeping the variable unchanged. For example, 6y + 3y = (3 + 6) y = 9y.
Step 3: Keep the sign in mind, pay attention to the signs (+/−) of each term when adding or subtracting. 10y -15y = -5y.
Unlike, terms cannot be added or subtracted because they have different variables or different exponents, making them impossible to combine. Here’s how to handle them:
Step 1: Do not combine unlike terms. Instead, leave them as they are. For example, 3x + 7y cannot be simplified, so it stays as it is.
Step 2: Write them in a simplified and organized manner, without combining them.
Like and unlike terms aren’t just for solving equations in class, they also help us to solve practical, real-life problems. Here are some real-life applications of like and unlike algebraic terms.
Understanding the difference between like and unlike terms in algebra is important. But many students find it hard and make simple mistakes that lead to wrong answers. Here are some common mistakes with tips to avoid them:
Are the terms 4x, −7x, and 9x like terms?
Yes, the terms are like terms.
All three terms have the same variable, which is x raised to the same power. Only the coefficients are different.
Simplify: 3a + 7a
10a
Both terms have the same variable a, they are like terms. Add the coefficients:
3 + 7=10 and add the variable a.
Simplify: 8x −5x
3x
They are like terms with the same variable x. So subtract coefficients:
8x − 5x = 3x
Simplify: 2x + 3y
It is an unlike term.
x and y are different variables, so they are unlike terms and cannot be combined.
Simplify: 4x + 3y + 5x + 2y
(4x + 5x) + (3y + 2y) = 9x + 5y
Here, we need to group terms with the same variable. 4x and 5x have the same variable (x), so group them together. Similarly, 3y and 2y are grouped together. Once the grouping is done, we can add the like terms. Grouping and adding only like terms gives us the answer 9x + 5y, which cannot be simplified further.
Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.
: He loves to play the quiz with kids through algebra to make kids love it.