Combining Like Terms

Terms that have the same variables raised to the same power are called “like terms”, where the numerical coefficients are different. Like terms are combined with each other to simplify the algebraic expressions.

For example: 7x, 10x, and -2x are like terms.

3x²y, -5x²y and 13x²y are like terms.

For example: -15a + 7a + 6b – 3a + 8a – 20b

Combining like terms we get,

(-15 + 7 – 3 + 8)a + (6 – 20)b

8a – 14b

Some facts about like terms:

• 2 × a is the same as 2a and is easier to write it as “2a” when we simplify an expression.
• 1 × b is the same as b.

Check Point:

Simplify the given expressions:

1. 21 + 24r – 71 – 9r
2. 13x + 5y – 8x – 12y + 20
3. 5a – 15b + 20a + 18b + 3
4. -2xy² + 5xy + 7xy² – 15xy + 20
5. 20a²b + 30a – 7b – 10a²b – 12a – 3b

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