Worked-out Problems
Worked-out Problems
Worked-out Problems
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Chapter 3 continued<br />
5. 11 2 3x<br />
The solution is 3.<br />
6. 5x 3 8.<br />
<br />
<br />
<br />
<br />
3. 1 2r 9 4. 2 6h 20<br />
1 9 2r 9 9 2 20 6h 20 20<br />
8 2r<br />
18 6h<br />
8<br />
2 r<br />
18 6h<br />
<br />
2 2<br />
6 6<br />
4 r<br />
3 h<br />
Check: 1 2r 9 Check: 2 6h 20<br />
1 2(4) 9 2 6(3) 20<br />
1 1 ✓ 2 2 ✓<br />
5. To solve 3x 7 5, add 7 to each side of the<br />
equation. To solve 3x 7 5, subtract 7 from each<br />
side of the equation.<br />
6. b 4 8 1 7. c 2 6<br />
6<br />
b 4 8 8 1 8 c 2 2 6 2<br />
6<br />
<br />
<br />
b 4 9 c 8<br />
6<br />
4 b 4 4(9) 6 c<br />
6 6(8)<br />
b 36 c 48<br />
Check: b 4 8 1 Check: c 2 6<br />
6<br />
3 6<br />
8<br />
4<br />
1 4 8<br />
2<br />
6<br />
6<br />
The solution is 1.<br />
7. The subtraction property of equality is used in Step 2.<br />
The division property of equality is used in Step 3.<br />
8. Step 1: 3x 6 12<br />
Step 2: 3x 6<br />
Step 3: x 2<br />
9. Sample answer: Subtract 1 from each side.<br />
2x 1 1 5 1<br />
2x 4<br />
Then divide each side by 2.<br />
2 x<br />
4 2 2 <br />
x 2<br />
3.1 Checkpoint (pp. 120–121)<br />
1. 4x 1 5 2. 3n 8 2<br />
4x 1 1 5 1 3n 8 8 2 8<br />
4x 4<br />
3n 6<br />
4 x<br />
4 4 4 3 n<br />
6<br />
<br />
3 3<br />
x 1<br />
n 2<br />
Check: 4x 1 5 Check: 3n 8 2<br />
4(1) 1 5 3(2) 8 2<br />
5 5 ✓ 2 2 ✓<br />
68 Pre-Algebra<br />
Chapter 3 <strong>Worked</strong>-Out Solution Key<br />
1 1 ✓ 6 6 ✓<br />
8. 2 d 5 1 9. 12 f 8<br />
2<br />
2 1 d 5 1 1 12 8 f 8 8<br />
2<br />
3 d 5 20 f <br />
2<br />
5(3) 5 d 5 2(20) 2 <br />
f<br />
2 <br />
15 d 40 f<br />
Check: 2 d 5 1 Check: 12 f 8<br />
2<br />
2 1 5<br />
1 12<br />
5<br />
4 0<br />
8<br />
2<br />
2 2 ✓ 12 12 ✓<br />
10. 12 4s 12<br />
12 4s 12 12 12<br />
4s 24<br />
4<br />
<br />
s<br />
4<br />
24<br />
<br />
4<br />
s 6<br />
Check: 12 4s 12<br />
12 4(6) 12<br />
1212 ✓<br />
Copyright © McDougal Littell/Houghton Mifflin Company<br />
All rights reserved.
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