Student's algebra homework assignment focusing on algebraic proofs and properties of equality.
A student's completed algebra homework worksheet titled "Unit 2: Logic & Proof - Homework 6: Algebraic Proof," featuring handwritten answers to questions about properties of equality and two-column proofs.
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Step-by-step solution for: SOLUTION: Unit 2 Logic and Proof Algebraic Proof Worksheet - Studypool
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Show Answer Key & Explanations
Step-by-step solution for: SOLUTION: Unit 2 Logic and Proof Algebraic Proof Worksheet - Studypool
Let's go through the homework step by step and correctly solve and explain each part. The assignment is about properties of equality and algebraic proofs.
---
We are given statements and must choose the correct property from the list (A–I).
#### 1. If $ a = 2b $, then $ a - c = 2b - c $
- We are subtracting $ c $ from both sides.
- This is the Subtraction Property of Equality.
- ✔ Answer: B
#### 2. $ x = x $
- A value is equal to itself.
- This is the Reflexive Property of Equality.
- ✔ Answer: G
#### 3. $ 3(p - 7) = 3p - 21 $
- Distributing the 3 across $ (p - 7) $
- This is the Distributive Property.
- ✔ Answer: E
#### 4. If $ -7k = -42 $, then $ k = 6 $
- Dividing both sides by $ -7 $
- This is the Division Property of Equality.
- ✔ Answer: D
#### 5. If $ m + n = 15 $ and $ n = 2 $, then $ m + 2 = 15 $
- Substituting $ n = 2 $ into the first equation.
- This is the Substitution Property.
- ✔ Answer: F
#### 6. If $ \frac{x}{4} = -5 $, then $ x = -20 $
- Multiplying both sides by 4
- This is the Multiplication Property of Equality.
- ✔ Answer: C
#### 7. If $ w^2 = 2x $ and $ 2x = y $, then $ w^2 = y $
- Since $ w^2 = 2x $ and $ 2x = y $, we can say $ w^2 = y $
- This is the Transitive Property.
- ✔ Answer: I
#### 8. If $ c - 9 = -1 $, then $ c = 8 $
- Adding 9 to both sides
- This is the Addition Property of Equality.
- ✔ Answer: A
#### 9. If $ n = -3 $, then $ -3 = n $
- Reversing the order of equality
- This is the Symmetric Property.
- ✔ Answer: H
---
✔ So far, all your answers in Part 1 are correct!
---
---
#### Problem 10: Given: $ -8(x - 3) = -32 $, Prove: $ x = 7 $
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality (subtract 24 from both sides) |
| $ x = 7 $ | Division Property of Equality (divide both sides by -8) |
> ✔ Your reasoning is mostly correct, but let’s fix the last step:
> - From $ -8x = -56 $, divide both sides by -8 → $ x = 7 $
> - So, reason is Division Property of Equality, not "Division Property of Equality" (you wrote it twice). Also, the second line is correct.
But wait — you wrote:
> $ -8x = -8 $ ← ✘ This is incorrect!
You said $ -8x = -8 $, but that’s wrong.
Let’s redo this correctly:
- $ -8x + 24 = -32 $
- Subtract 24: $ -8x = -32 - 24 = -56 $
- Then divide: $ x = (-56)/(-8) = 7 $
So, correct table:
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality |
| $ x = 7 $ | Division Property of Equality |
✔ You had a mistake in arithmetic in the third row. It should be $ -8x = -56 $, not $ -8 $. That’s a critical error.
---
#### Problem 11: Given: $ -16 = \frac{m}{5} - 18 $, Prove: $ m = 10 $
Let’s complete the proof step by step.
We’re given:
$$
-16 = \frac{m}{5} - 18
$$
We want to prove $ m = 10 $
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ -16 + 18 = \frac{m}{5} $ | Addition Property of Equality (add 18 to both sides) |
| $ 2 = \frac{m}{5} $ | Simplify |
| $ 10 = m $ | Multiplication Property of Equality (multiply both sides by 5) |
| $ m = 10 $ | Symmetric Property of Equality (reverse order) |
Now fill in the table as per your format:
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ 2 = \frac{m}{5} $ | Addition Property of Equality |
| $ 10 = m $ | Multiplication Property of Equality |
| $ m = 10 $ | Symmetric Property of Equality |
✔ So the missing steps are:
- Third row: $ 10 = m $ → Reason: Multiplication Property of Equality
- Fourth row: $ m = 10 $ → Reason: Symmetric Property of Equality
> Note: You might not need the last row if you stop at $ 10 = m $, since that implies $ m = 10 $. But if they want the conclusion written as $ m = 10 $, then use Symmetric Property.
---
#### Part 1: Properties
1. B – Subtraction Property
2. G – Reflexive Property
3. E – Distributive Property
4. D – Division Property
5. F – Substitution Property
6. C – Multiplication Property
7. I – Transitive Property
8. A – Addition Property
9. H – Symmetric Property
✔ All correct!
---
#### Part 2: Proofs
Problem 10: Fix the mistake
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality |
| $ x = 7 $ | Division Property of Equality |
✘ You wrote $ -8x = -8 $, which is incorrect.
Problem 11: Fill in the rest
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ 2 = \frac{m}{5} $ | Addition Property of Equality |
| $ 10 = m $ | Multiplication Property of Equality |
| $ m = 10 $ | Symmetric Property of Equality |
✔ You were on the right track, but missed the final two steps.
---
- Always double-check arithmetic in algebraic proofs.
- The order of operations and properties matter.
- Use Symmetric Property when flipping equations (e.g., $ a = b $ → $ b = a $).
- Use Substitution when replacing a variable with its equivalent.
- Transitive Property: If $ a = b $ and $ b = c $, then $ a = c $
---
✔ Final Answer:
- Part 1: All answers are correct.
- Part 2:
- Problem 10: Corrected the mistake: $ -8x = -56 $, not $ -8 $
- Problem 11: Add rows:
- $ 10 = m $ → Multiplication Property of Equality
- $ m = 10 $ → Symmetric Property of Equality
Let me know if you'd like this formatted for printing or submission!
---
✔ Part 1: Name the property of equality that justifies each statement.
We are given statements and must choose the correct property from the list (A–I).
#### 1. If $ a = 2b $, then $ a - c = 2b - c $
- We are subtracting $ c $ from both sides.
- This is the Subtraction Property of Equality.
- ✔ Answer: B
#### 2. $ x = x $
- A value is equal to itself.
- This is the Reflexive Property of Equality.
- ✔ Answer: G
#### 3. $ 3(p - 7) = 3p - 21 $
- Distributing the 3 across $ (p - 7) $
- This is the Distributive Property.
- ✔ Answer: E
#### 4. If $ -7k = -42 $, then $ k = 6 $
- Dividing both sides by $ -7 $
- This is the Division Property of Equality.
- ✔ Answer: D
#### 5. If $ m + n = 15 $ and $ n = 2 $, then $ m + 2 = 15 $
- Substituting $ n = 2 $ into the first equation.
- This is the Substitution Property.
- ✔ Answer: F
#### 6. If $ \frac{x}{4} = -5 $, then $ x = -20 $
- Multiplying both sides by 4
- This is the Multiplication Property of Equality.
- ✔ Answer: C
#### 7. If $ w^2 = 2x $ and $ 2x = y $, then $ w^2 = y $
- Since $ w^2 = 2x $ and $ 2x = y $, we can say $ w^2 = y $
- This is the Transitive Property.
- ✔ Answer: I
#### 8. If $ c - 9 = -1 $, then $ c = 8 $
- Adding 9 to both sides
- This is the Addition Property of Equality.
- ✔ Answer: A
#### 9. If $ n = -3 $, then $ -3 = n $
- Reversing the order of equality
- This is the Symmetric Property.
- ✔ Answer: H
---
✔ So far, all your answers in Part 1 are correct!
---
✔ Part 2: Complete each proof using properties of equality
---
#### Problem 10: Given: $ -8(x - 3) = -32 $, Prove: $ x = 7 $
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality (subtract 24 from both sides) |
| $ x = 7 $ | Division Property of Equality (divide both sides by -8) |
> ✔ Your reasoning is mostly correct, but let’s fix the last step:
> - From $ -8x = -56 $, divide both sides by -8 → $ x = 7 $
> - So, reason is Division Property of Equality, not "Division Property of Equality" (you wrote it twice). Also, the second line is correct.
But wait — you wrote:
> $ -8x = -8 $ ← ✘ This is incorrect!
You said $ -8x = -8 $, but that’s wrong.
Let’s redo this correctly:
- $ -8x + 24 = -32 $
- Subtract 24: $ -8x = -32 - 24 = -56 $
- Then divide: $ x = (-56)/(-8) = 7 $
So, correct table:
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality |
| $ x = 7 $ | Division Property of Equality |
✔ You had a mistake in arithmetic in the third row. It should be $ -8x = -56 $, not $ -8 $. That’s a critical error.
---
#### Problem 11: Given: $ -16 = \frac{m}{5} - 18 $, Prove: $ m = 10 $
Let’s complete the proof step by step.
We’re given:
$$
-16 = \frac{m}{5} - 18
$$
We want to prove $ m = 10 $
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ -16 + 18 = \frac{m}{5} $ | Addition Property of Equality (add 18 to both sides) |
| $ 2 = \frac{m}{5} $ | Simplify |
| $ 10 = m $ | Multiplication Property of Equality (multiply both sides by 5) |
| $ m = 10 $ | Symmetric Property of Equality (reverse order) |
Now fill in the table as per your format:
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ 2 = \frac{m}{5} $ | Addition Property of Equality |
| $ 10 = m $ | Multiplication Property of Equality |
| $ m = 10 $ | Symmetric Property of Equality |
✔ So the missing steps are:
- Third row: $ 10 = m $ → Reason: Multiplication Property of Equality
- Fourth row: $ m = 10 $ → Reason: Symmetric Property of Equality
> Note: You might not need the last row if you stop at $ 10 = m $, since that implies $ m = 10 $. But if they want the conclusion written as $ m = 10 $, then use Symmetric Property.
---
✔ Final Answers Summary
#### Part 1: Properties
1. B – Subtraction Property
2. G – Reflexive Property
3. E – Distributive Property
4. D – Division Property
5. F – Substitution Property
6. C – Multiplication Property
7. I – Transitive Property
8. A – Addition Property
9. H – Symmetric Property
✔ All correct!
---
#### Part 2: Proofs
Problem 10: Fix the mistake
| Statements | Reasons |
|-----------|--------|
| $ -8(x - 3) = -32 $ | Given |
| $ -8x + 24 = -32 $ | Distributive Property |
| $ -8x = -56 $ | Subtraction Property of Equality |
| $ x = 7 $ | Division Property of Equality |
✘ You wrote $ -8x = -8 $, which is incorrect.
Problem 11: Fill in the rest
| Statements | Reasons |
|-----------|--------|
| $ -16 = \frac{m}{5} - 18 $ | Given |
| $ 2 = \frac{m}{5} $ | Addition Property of Equality |
| $ 10 = m $ | Multiplication Property of Equality |
| $ m = 10 $ | Symmetric Property of Equality |
✔ You were on the right track, but missed the final two steps.
---
📝 Final Notes
- Always double-check arithmetic in algebraic proofs.
- The order of operations and properties matter.
- Use Symmetric Property when flipping equations (e.g., $ a = b $ → $ b = a $).
- Use Substitution when replacing a variable with its equivalent.
- Transitive Property: If $ a = b $ and $ b = c $, then $ a = c $
---
✔ Final Answer:
- Part 1: All answers are correct.
- Part 2:
- Problem 10: Corrected the mistake: $ -8x = -56 $, not $ -8 $
- Problem 11: Add rows:
- $ 10 = m $ → Multiplication Property of Equality
- $ m = 10 $ → Symmetric Property of Equality
Let me know if you'd like this formatted for printing or submission!
Parent Tip: Review the logic above to help your child master the concept of reasoning in algebra and geometry worksheet.