9. $$ -4(r+2)=4(2-2 r) \quad $$ 10. $$ 1.3+6 d=2.7-8 d $$

Question

UpStudy AI · Accepted Answer

Sure, let's solve each equation step by step.

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### **Problem 9:**
$$
-4(r + 2) = 4(2 - 2r)
$$

**Step 1: Distribute the constants on both sides.**
$$
-4 \cdot r - 4 \cdot 2 = 4 \cdot 2 - 4 \cdot 2r
$$
$$
-4r - 8 = 8 - 8r
$$

**Step 2: Get all $$ r $$-terms on one side and constants on the other.**
$$
-4r + 8r = 8 + 8
$$
$$
4r = 16
$$

**Step 3: Solve for $$ r $$.**
$$
r = \frac{16}{4} = 4
$$

**Answer:** $$ r = 4 $$

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### **Problem 10:**
$$
1.3 + 6d = 2.7 - 8d
$$

**Step 1: Get all $$ d $$-terms on one side and constants on the other.**

Add $$ 8d $$ to both sides:
$$
1.3 + 6d + 8d = 2.7
$$
$$
1.3 + 14d = 2.7
$$

**Step 2: Subtract $$ 1.3 $$ from both sides to isolate the $$ d $$-terms.**
$$
14d = 2.7 - 1.3
$$
$$
14d = 1.4
$$

**Step 3: Solve for $$ d $$.**
$$
d = \frac{1.4}{14} = 0.1
$$

**Answer:** $$ d = 0.1 $$

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If you have any further questions or need additional explanations, feel free to ask!
**Problem 9:** $$ r = 4 $$ **Problem 10:** $$ d = 0.1 $$

9. \( -4(r+2)=4(2-2 r) \quad \) 10. \( 1.3+6 d=2.7-8 d \)