Let's solve each problem on the
Square Roots Worksheet step by step and explain the reasoning.
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1a. $\sqrt{49} \times \sqrt{49}$
- $\sqrt{49} = 7$, because $7 \times 7 = 49$
- So, $7 \times 7 = 49$
✔ Answer: 49
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1b. $(\sqrt{16})^2$
- $\sqrt{16} = 4$, because $4 \times 4 = 16$
- Then, $4^2 = 16$
✔ Answer: 16
> *Note:* Squaring a square root cancels out the square root: $(\sqrt{a})^2 = a$
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2a. $\sqrt{2 \times 8}$
- First, simplify inside the square root: $2 \times 8 = 16$
- $\sqrt{16} = 4$
✔ Answer: 4
> *Alternative way:* $\sqrt{2 \times 8} = \sqrt{16} = 4$
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2b. $\sqrt{36} - \sqrt{81}$
- $\sqrt{36} = 6$
- $\sqrt{81} = 9$
- $6 - 9 = -3$
✔ Answer: -3
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3a. $\sqrt{91 - 27}$
- First, subtract: $91 - 27 = 64$
- $\sqrt{64} = 8$
✔ Answer: 8
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3b. $\sqrt{\frac{490}{10}}$
- Simplify inside: $\frac{490}{10} = 49$
- $\sqrt{49} = 7$
✔ Answer: 7
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4a. $\sqrt{24^2}$
- $24^2 = 576$
- $\sqrt{576} = 24$
✔ Answer: 24
> *Note:* $\sqrt{a^2} = |a|$, but since $24 > 0$, it's just $24$
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4b. $\sqrt{49} + \sqrt{100}$
- $\sqrt{49} = 7$
- $\sqrt{100} = 10$
- $7 + 10 = 17$
✔ Answer: 17
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5a. $\sqrt{49 + 0}$
- $49 + 0 = 49$
- $\sqrt{49} = 7$
✔ Answer: 7
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5b. $\sqrt{9} \times \sqrt{49}$
- $\sqrt{9} = 3$
- $\sqrt{49} = 7$
- $3 \times 7 = 21$
✔ Answer: 21
> *Property:* $\sqrt{a} \times \sqrt{b} = \sqrt{a \times b}$
> So, $\sqrt{9} \times \sqrt{49} = \sqrt{9 \times 49} = \sqrt{441} = 21$
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6a. $\frac{\sqrt{100}}{\sqrt{4}}$
- $\sqrt{100} = 10$
- $\sqrt{4} = 2$
- $\frac{10}{2} = 5$
✔ Answer: 5
> *Property:* $\frac{\sqrt{a}}{\sqrt{b}} = \sqrt{\frac{a}{b}}$
> So, $\frac{\sqrt{100}}{\sqrt{4}} = \sqrt{\frac{100}{4}} = \sqrt{25} = 5$
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6b. $(\sqrt{100})^2$
- $\sqrt{100} = 10$
- $10^2 = 100$
✔ Answer: 100
> Again, squaring a square root cancels it: $(\sqrt{a})^2 = a$
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✔ Final Answers:
| Problem | Answer |
|--------|--------|
| 1a | 49 |
| 1b | 16 |
| 2a | 4 |
| 2b | -3 |
| 3a | 8 |
| 3b | 7 |
| 4a | 24 |
| 4b | 17 |
| 5a | 7 |
| 5b | 21 |
| 6a | 5 |
| 6b | 100 |
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Let me know if you'd like this formatted as a printable answer key!
Parent Tip: Review the logic above to help your child master the concept of square root worksheet 8th grade.