"Like Terms" means that you can add or subtract two terms. For instance, you know that you can add 2 +3 and get 5. You were able to add these two 'terms' ( the '2' and the '3') becuase they are both numbers! However, you might also know that you cannot 'combine' 2 and x. Since 2 is a number and 'x' is not, they are not like terms.

Exponents and Bases: You may have noticed that like terms always have the same base and exponent.

Regarding Coefficients: Also, the coefficient in front of a variable does not change whether or not terms are alike. For instance 3x and 5x and 11x are all like terms. The coeffiecients ( the '3' in 3x, '5' in 5x and '11' in 11x) do not have anything at all to do with whether or not the terms are like. All that matters is that each of 'x' factors or 'bases' have the same exponent.

Practice Combining Like Terms

Easier Problems

Practice Problem 1)
Combine the like terms below.

x + 2 +2x

Answer

x and 2x are like terms so you combine, or add, them to become 3x. Therefore the final answer is 3x +2

Practice Problem 2)
Combine the like terms below.

5+ x + 2

Answer

5 and 2 are like terms so you can combine them to become 7. Therefore the final answer is 7 +x

Practice Problem 2)
Combine the like terms below.

3x + 2x + 6

Answer

3x and 2x are like terms (Remember the coefficientsdo not matter) so you can combine (ie 'add') them to become 5x. The final answer is 5x + 6

Problem 3)
Use your knowledge of like terms to simplify.

2x + 3 + x + 6

Answer

2x and x are like terms so you can combine (ie 'add') them to become 3x. Likewise, 3 and 6 are like terms and can be added to 9. The final answer is 3x + 9

More Challenging problems

Problem 4)
Use your knowledge of like terms to simplify.

2x^{2} + 13 + x^{2} + 6

Answer

2x^{2} and x^{2} are like terms so you can combine (ie 'add') them to become 3x^{2}. Likewise, 13 and 6 are like terms and can be added to 19. The final answer is 3x^{2} + 19

Problem 5)
Use your knowledge of like terms to simplify.

2x^{3} + 3x + x^{2} + 4x^{3}

Answer

2x^{3} and 4x^{3} are the only like terms --combine (ie 'add') them to become 6x^{3}. Likewise, 13 and 6 are like terms and can be added to 19. The final answer is 6x^{3} +x^{2} + 3x