Math worksheet for practicing multiplication and division of radical expressions, featuring 15 problems to simplify.
Worksheet titled "Multiply and Divide Radical Expressions" with problems involving simplifying radical expressions and operations with radicals.
JPG
495×640
17.8 KB
Free · Personal Use
Quality Assured by Worksheets Library Team
Reviewed for educational accuracy and age-appropriateness
ID: #350688
⭐
Show Answer Key & Explanations
Step-by-step solution for: Multiply and Divide Radical Expressions
▼
Show Answer Key & Explanations
Step-by-step solution for: Multiply and Divide Radical Expressions
Let's solve each problem step by step, starting with the basic multiplication and division of radical expressions, followed by simplifying the more complex expressions.
---
We'll evaluate these basic operations:
1. $ 2 \cdot 5 = \boxed{10} $
2. $ 2 \cdot \sqrt{5} = \boxed{2\sqrt{5}} $
3. $ \sqrt{2} \cdot 5 = \boxed{5\sqrt{2}} $
4. $ \sqrt{2} \cdot \sqrt{5} = \sqrt{2 \cdot 5} = \boxed{\sqrt{10}} $
5. $ 2\sqrt{3} \cdot 5 = 10\sqrt{3} $ → $ \boxed{10\sqrt{3}} $
6. $ 2\sqrt{3} \cdot \sqrt{6} = 2 \cdot \sqrt{3 \cdot 6} = 2\sqrt{18} = 2 \cdot \sqrt{9 \cdot 2} = 2 \cdot 3\sqrt{2} = \boxed{6\sqrt{2}} $
7. $ 2\sqrt{3} \cdot 4\sqrt{5} = (2 \cdot 4) \cdot \sqrt{3 \cdot 5} = 8\sqrt{15} $ → $ \boxed{8\sqrt{15}} $
---
We now simplify each expression:
---
1. $ \sqrt{5} \cdot \sqrt{7} $
$$
= \sqrt{5 \cdot 7} = \boxed{\sqrt{35}}
$$
---
2. $ \sqrt{3} \cdot \sqrt{21} $
$$
= \sqrt{3 \cdot 21} = \sqrt{63} = \sqrt{9 \cdot 7} = 3\sqrt{7} \rightarrow \boxed{3\sqrt{7}}
$$
---
3. $ \sqrt{10} \cdot \sqrt{50} $
$$
= \sqrt{10 \cdot 50} = \sqrt{500} = \sqrt{100 \cdot 5} = 10\sqrt{5} \rightarrow \boxed{10\sqrt{5}}
$$
---
4. $ 4(\sqrt{2} - \sqrt{7}) $
Distribute:
$$
= 4\sqrt{2} - 4\sqrt{7} \rightarrow \boxed{4\sqrt{2} - 4\sqrt{7}}
$$
---
5. $ \sqrt{5}(6 - \sqrt{5}) $
Distribute:
$$
= 6\sqrt{5} - \sqrt{5} \cdot \sqrt{5} = 6\sqrt{5} - 5 \rightarrow \boxed{6\sqrt{5} - 5}
$$
---
6. $ 2\sqrt{3}(2\sqrt{3} - 4\sqrt{5}) $
Distribute:
$$
= 2\sqrt{3} \cdot 2\sqrt{3} - 2\sqrt{3} \cdot 4\sqrt{5} = 4 \cdot 3 - 8\sqrt{15} = 12 - 8\sqrt{15} \rightarrow \boxed{12 - 8\sqrt{15}}
$$
---
7. $ \sqrt{7}(4\sqrt{7} - 2\sqrt{3}) $
Distribute:
$$
= \sqrt{7} \cdot 4\sqrt{7} - \sqrt{7} \cdot 2\sqrt{3} = 4 \cdot 7 - 2\sqrt{21} = 28 - 2\sqrt{21} \rightarrow \boxed{28 - 2\sqrt{21}}
$$
---
8. $ \sqrt{3x}(\sqrt{6x} - \sqrt{12}) $
Distribute:
$$
= \sqrt{3x} \cdot \sqrt{6x} - \sqrt{3x} \cdot \sqrt{12}
$$
First term:
$$
\sqrt{3x \cdot 6x} = \sqrt{18x^2} = \sqrt{9 \cdot 2 \cdot x^2} = 3x\sqrt{2}
$$
Second term:
$$
\sqrt{3x \cdot 12} = \sqrt{36x} = \sqrt{36} \cdot \sqrt{x} = 6\sqrt{x}
$$
So:
$$
= 3x\sqrt{2} - 6\sqrt{x} \rightarrow \boxed{3x\sqrt{2} - 6\sqrt{x}}
$$
---
9. $ 3\sqrt{2}(\sqrt{2} - 4) + \sqrt{2}(5 - \sqrt{2}) $
Break into two parts:
First part:
$$
3\sqrt{2} \cdot \sqrt{2} - 3\sqrt{2} \cdot 4 = 3 \cdot 2 - 12\sqrt{2} = 6 - 12\sqrt{2}
$$
Second part:
$$
\sqrt{2} \cdot 5 - \sqrt{2} \cdot \sqrt{2} = 5\sqrt{2} - 2
$$
Now add both:
$$
(6 - 12\sqrt{2}) + (5\sqrt{2} - 2) = (6 - 2) + (-12\sqrt{2} + 5\sqrt{2}) = 4 - 7\sqrt{2} \rightarrow \boxed{4 - 7\sqrt{2}}
$$
---
10. $ (\sqrt{6} - 3)(\sqrt{6} + 4) $
Use distributive property (FOIL):
$$
= \sqrt{6} \cdot \sqrt{6} + \sqrt{6} \cdot 4 - 3 \cdot \sqrt{6} - 3 \cdot 4
= 6 + 4\sqrt{6} - 3\sqrt{6} - 12
= (6 - 12) + (4\sqrt{6} - 3\sqrt{6}) = -6 + \sqrt{6} \rightarrow \boxed{-6 + \sqrt{6}}
$$
---
11. $ (\sqrt{m} - \sqrt{5})^2 $
Use formula: $ (a - b)^2 = a^2 - 2ab + b^2 $
$$
= (\sqrt{m})^2 - 2\sqrt{m}\sqrt{5} + (\sqrt{5})^2 = m - 2\sqrt{5m} + 5 \rightarrow \boxed{m + 5 - 2\sqrt{5m}}
$$
---
12. $ (5\sqrt{x} + 2)(2\sqrt{x} - 1) $
FOIL:
$$
= 5\sqrt{x} \cdot 2\sqrt{x} + 5\sqrt{x} \cdot (-1) + 2 \cdot 2\sqrt{x} + 2 \cdot (-1)
= 10x - 5\sqrt{x} + 4\sqrt{x} - 2
= 10x - \sqrt{x} - 2 \rightarrow \boxed{10x - \sqrt{x} - 2}
$$
---
13. $ (\sqrt{5} - x)(\sqrt{5} + x) $
This is a difference of squares:
$$
= (\sqrt{5})^2 - x^2 = 5 - x^2 \rightarrow \boxed{5 - x^2}
$$
---
14. $ (5\sqrt{2} + 3)(\sqrt{2} - 3) $
FOIL:
$$
= 5\sqrt{2} \cdot \sqrt{2} + 5\sqrt{2} \cdot (-3) + 3 \cdot \sqrt{2} + 3 \cdot (-3)
= 5 \cdot 2 - 15\sqrt{2} + 3\sqrt{2} - 9
= 10 - 15\sqrt{2} + 3\sqrt{2} - 9
= (10 - 9) + (-15\sqrt{2} + 3\sqrt{2}) = 1 - 12\sqrt{2} \rightarrow \boxed{1 - 12\sqrt{2}}
$$
---
15. $ (3 + 2\sqrt{5})^2 $
Use $ (a + b)^2 = a^2 + 2ab + b^2 $
$$
= 3^2 + 2 \cdot 3 \cdot 2\sqrt{5} + (2\sqrt{5})^2
= 9 + 12\sqrt{5} + 4 \cdot 5
= 9 + 12\sqrt{5} + 20 = 29 + 12\sqrt{5} \rightarrow \boxed{29 + 12\sqrt{5}}
$$
---
#### Part 1:
1. $ 10 $
2. $ 2\sqrt{5} $
3. $ 5\sqrt{2} $
4. $ \sqrt{10} $
5. $ 10\sqrt{3} $
6. $ 6\sqrt{2} $
7. $ 8\sqrt{15} $
#### Part 2:
1. $ \sqrt{35} $
2. $ 3\sqrt{7} $
3. $ 10\sqrt{5} $
4. $ 4\sqrt{2} - 4\sqrt{7} $
5. $ 6\sqrt{5} - 5 $
6. $ 12 - 8\sqrt{15} $
7. $ 28 - 2\sqrt{21} $
8. $ 3x\sqrt{2} - 6\sqrt{x} $
9. $ 4 - 7\sqrt{2} $
10. $ -6 + \sqrt{6} $
11. $ m + 5 - 2\sqrt{5m} $
12. $ 10x - \sqrt{x} - 2 $
13. $ 5 - x^2 $
14. $ 1 - 12\sqrt{2} $
15. $ 29 + 12\sqrt{5} $
Let me know if you'd like a visual explanation or further breakdown!
---
Part 1: Multiply and Divide Radical Expressions
We'll evaluate these basic operations:
1. $ 2 \cdot 5 = \boxed{10} $
2. $ 2 \cdot \sqrt{5} = \boxed{2\sqrt{5}} $
3. $ \sqrt{2} \cdot 5 = \boxed{5\sqrt{2}} $
4. $ \sqrt{2} \cdot \sqrt{5} = \sqrt{2 \cdot 5} = \boxed{\sqrt{10}} $
5. $ 2\sqrt{3} \cdot 5 = 10\sqrt{3} $ → $ \boxed{10\sqrt{3}} $
6. $ 2\sqrt{3} \cdot \sqrt{6} = 2 \cdot \sqrt{3 \cdot 6} = 2\sqrt{18} = 2 \cdot \sqrt{9 \cdot 2} = 2 \cdot 3\sqrt{2} = \boxed{6\sqrt{2}} $
7. $ 2\sqrt{3} \cdot 4\sqrt{5} = (2 \cdot 4) \cdot \sqrt{3 \cdot 5} = 8\sqrt{15} $ → $ \boxed{8\sqrt{15}} $
---
Part 2: Perform the indicated operations and simplify
We now simplify each expression:
---
1. $ \sqrt{5} \cdot \sqrt{7} $
$$
= \sqrt{5 \cdot 7} = \boxed{\sqrt{35}}
$$
---
2. $ \sqrt{3} \cdot \sqrt{21} $
$$
= \sqrt{3 \cdot 21} = \sqrt{63} = \sqrt{9 \cdot 7} = 3\sqrt{7} \rightarrow \boxed{3\sqrt{7}}
$$
---
3. $ \sqrt{10} \cdot \sqrt{50} $
$$
= \sqrt{10 \cdot 50} = \sqrt{500} = \sqrt{100 \cdot 5} = 10\sqrt{5} \rightarrow \boxed{10\sqrt{5}}
$$
---
4. $ 4(\sqrt{2} - \sqrt{7}) $
Distribute:
$$
= 4\sqrt{2} - 4\sqrt{7} \rightarrow \boxed{4\sqrt{2} - 4\sqrt{7}}
$$
---
5. $ \sqrt{5}(6 - \sqrt{5}) $
Distribute:
$$
= 6\sqrt{5} - \sqrt{5} \cdot \sqrt{5} = 6\sqrt{5} - 5 \rightarrow \boxed{6\sqrt{5} - 5}
$$
---
6. $ 2\sqrt{3}(2\sqrt{3} - 4\sqrt{5}) $
Distribute:
$$
= 2\sqrt{3} \cdot 2\sqrt{3} - 2\sqrt{3} \cdot 4\sqrt{5} = 4 \cdot 3 - 8\sqrt{15} = 12 - 8\sqrt{15} \rightarrow \boxed{12 - 8\sqrt{15}}
$$
---
7. $ \sqrt{7}(4\sqrt{7} - 2\sqrt{3}) $
Distribute:
$$
= \sqrt{7} \cdot 4\sqrt{7} - \sqrt{7} \cdot 2\sqrt{3} = 4 \cdot 7 - 2\sqrt{21} = 28 - 2\sqrt{21} \rightarrow \boxed{28 - 2\sqrt{21}}
$$
---
8. $ \sqrt{3x}(\sqrt{6x} - \sqrt{12}) $
Distribute:
$$
= \sqrt{3x} \cdot \sqrt{6x} - \sqrt{3x} \cdot \sqrt{12}
$$
First term:
$$
\sqrt{3x \cdot 6x} = \sqrt{18x^2} = \sqrt{9 \cdot 2 \cdot x^2} = 3x\sqrt{2}
$$
Second term:
$$
\sqrt{3x \cdot 12} = \sqrt{36x} = \sqrt{36} \cdot \sqrt{x} = 6\sqrt{x}
$$
So:
$$
= 3x\sqrt{2} - 6\sqrt{x} \rightarrow \boxed{3x\sqrt{2} - 6\sqrt{x}}
$$
---
9. $ 3\sqrt{2}(\sqrt{2} - 4) + \sqrt{2}(5 - \sqrt{2}) $
Break into two parts:
First part:
$$
3\sqrt{2} \cdot \sqrt{2} - 3\sqrt{2} \cdot 4 = 3 \cdot 2 - 12\sqrt{2} = 6 - 12\sqrt{2}
$$
Second part:
$$
\sqrt{2} \cdot 5 - \sqrt{2} \cdot \sqrt{2} = 5\sqrt{2} - 2
$$
Now add both:
$$
(6 - 12\sqrt{2}) + (5\sqrt{2} - 2) = (6 - 2) + (-12\sqrt{2} + 5\sqrt{2}) = 4 - 7\sqrt{2} \rightarrow \boxed{4 - 7\sqrt{2}}
$$
---
10. $ (\sqrt{6} - 3)(\sqrt{6} + 4) $
Use distributive property (FOIL):
$$
= \sqrt{6} \cdot \sqrt{6} + \sqrt{6} \cdot 4 - 3 \cdot \sqrt{6} - 3 \cdot 4
= 6 + 4\sqrt{6} - 3\sqrt{6} - 12
= (6 - 12) + (4\sqrt{6} - 3\sqrt{6}) = -6 + \sqrt{6} \rightarrow \boxed{-6 + \sqrt{6}}
$$
---
11. $ (\sqrt{m} - \sqrt{5})^2 $
Use formula: $ (a - b)^2 = a^2 - 2ab + b^2 $
$$
= (\sqrt{m})^2 - 2\sqrt{m}\sqrt{5} + (\sqrt{5})^2 = m - 2\sqrt{5m} + 5 \rightarrow \boxed{m + 5 - 2\sqrt{5m}}
$$
---
12. $ (5\sqrt{x} + 2)(2\sqrt{x} - 1) $
FOIL:
$$
= 5\sqrt{x} \cdot 2\sqrt{x} + 5\sqrt{x} \cdot (-1) + 2 \cdot 2\sqrt{x} + 2 \cdot (-1)
= 10x - 5\sqrt{x} + 4\sqrt{x} - 2
= 10x - \sqrt{x} - 2 \rightarrow \boxed{10x - \sqrt{x} - 2}
$$
---
13. $ (\sqrt{5} - x)(\sqrt{5} + x) $
This is a difference of squares:
$$
= (\sqrt{5})^2 - x^2 = 5 - x^2 \rightarrow \boxed{5 - x^2}
$$
---
14. $ (5\sqrt{2} + 3)(\sqrt{2} - 3) $
FOIL:
$$
= 5\sqrt{2} \cdot \sqrt{2} + 5\sqrt{2} \cdot (-3) + 3 \cdot \sqrt{2} + 3 \cdot (-3)
= 5 \cdot 2 - 15\sqrt{2} + 3\sqrt{2} - 9
= 10 - 15\sqrt{2} + 3\sqrt{2} - 9
= (10 - 9) + (-15\sqrt{2} + 3\sqrt{2}) = 1 - 12\sqrt{2} \rightarrow \boxed{1 - 12\sqrt{2}}
$$
---
15. $ (3 + 2\sqrt{5})^2 $
Use $ (a + b)^2 = a^2 + 2ab + b^2 $
$$
= 3^2 + 2 \cdot 3 \cdot 2\sqrt{5} + (2\sqrt{5})^2
= 9 + 12\sqrt{5} + 4 \cdot 5
= 9 + 12\sqrt{5} + 20 = 29 + 12\sqrt{5} \rightarrow \boxed{29 + 12\sqrt{5}}
$$
---
✔ Final Answers Summary:
#### Part 1:
1. $ 10 $
2. $ 2\sqrt{5} $
3. $ 5\sqrt{2} $
4. $ \sqrt{10} $
5. $ 10\sqrt{3} $
6. $ 6\sqrt{2} $
7. $ 8\sqrt{15} $
#### Part 2:
1. $ \sqrt{35} $
2. $ 3\sqrt{7} $
3. $ 10\sqrt{5} $
4. $ 4\sqrt{2} - 4\sqrt{7} $
5. $ 6\sqrt{5} - 5 $
6. $ 12 - 8\sqrt{15} $
7. $ 28 - 2\sqrt{21} $
8. $ 3x\sqrt{2} - 6\sqrt{x} $
9. $ 4 - 7\sqrt{2} $
10. $ -6 + \sqrt{6} $
11. $ m + 5 - 2\sqrt{5m} $
12. $ 10x - \sqrt{x} - 2 $
13. $ 5 - x^2 $
14. $ 1 - 12\sqrt{2} $
15. $ 29 + 12\sqrt{5} $
Let me know if you'd like a visual explanation or further breakdown!
Parent Tip: Review the logic above to help your child master the concept of multiplying and dividing radicals worksheet answers.