1. 11-2: Operations with Radical Expressions
Essential Question: How do you add and subtract radicals?

2. 11-2: Operations With Radical Expressions
Like Radicals: Radicals that have the same radicand (term underneath the root)
Like radicals, similar to like terms, can be added and subtracted.
Example 1: Combining Like Radicals
Simplify
Both terms contain , so they can be combined
If there is no number in front of a radical, assume a “1”

3. 11-2: Operations With Radical Expressions
Your Turn: Simplify each expression

4. 11-2: Operations With Radical Expressions
Sometimes, radicals that don’t appear to be like terms can be combined if you simplify all radicals.
Example 2: Simplifying to Combine Like Radicals
Simplify
12 can be broken down: 2 ● 2 ● 3 =

5. 11-2: Operations With Radical Expressions
Your Turn: Simplify each expression

6. 11-2: Operations With Radical Expressions
When simplifying an expression like , use the distributive property to multiply the outside term with all inside terms.
Remember: Numbers under roots can multiply with numbers under roots only.
Simplify
18 can be simplified (3 ● 3 ● 2)

7. 11-2: Operations With Radical Expressions
Your Turn: Simplify each expression

8. 11-2: Operations With Radical Expressions
If both radicals have two terms, you can multiply the same way you do two binomials – by using FOIL
Example 4: Using FOIL
Simplify
First:
Outer:
Inner:
Last:
Put it all together:

9. 11-2: Operations With Radical Expressions
Your Turn: Simplify each expression

10. 11-2: Operations With Radical Expressions
Conjugates: The sum and difference of the same two terms. The product of two conjugates results in the difference of two squares.
Notice that the product of conjugates no longer has a radical.
This becomes important when rationalizing a denominator that has two terms

11. 11-2: Operations With Radical Expressions
Example 5: Rationalizing a Denominator Using Conjugates
Simplify
Need to get rid of square roots in denominator, so multiply top and bottom of the fraction by the conjugate of the denominator. Top is distribution (or FOIL), bottom is FOILed
Divide all #s outside by 3

12. 11-2: Operations With Radical Expressions
Your Turn: Simplify each expression

13. 11-2: Operations With Radical Expressions
Assignment
Worksheet #11-2
Problems 1 – 45, odds