Day 20 – Adding and subtracting radical expressions

TEXT: Intermediate Algebra by Miller, O’Neill & Hyde

Videos from a variety of sources, including Khan Academy.

To add or subtract polynomials, we combined like terms. In some sense, we extend the notion of “like” developed with polynomials to radicals.

Since we are working only with square roots (index 2), we can simplify the statement to:

DEFINITION Like Radicals

Two terms with square roots are called like radicals if they have the same radicand.

To combine like radicals, we factor out the radical (using the distributive property in reverse) . In your homework, you will often have to simplify the radicals before you combine the like radicals. See coolmath or purplemath for detail and examples with just numbers. Some videos with just numbers:

The mathportal has examples, explanation and exercises with numbers as well as with variables. An example with numbers and then one with variables (you may ignore the last example which is with a cube root):

An example with variables:

3 Responses to Day 20 – Adding and subtracting radical expressions

  1. Professor Halleck
    Rebecca Kogan

    This is the easiest topic so far :) for me, at least. Again, the videos here are very helpful.

  2. Hibba Abbas says:

    Adding and subtracting radical expressions are easy, but the steps to solve them are longer.

  3. awiltshire says:

    It not that hard, just need to do practice questions and it will be simple

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