Name
T E K S 2A.2.A
LESSON
7-4
Date
Class
Practice B
Properties of Logarithms
Express as a single logarithm. Simplify, if possible.
1. log 3 9 ⫹ log 3 27
2. log 2 8 ⫹ log 2 16
3. log 10 80 ⫹ log 10 125
4. log 6 8 ⫹ log 6 27
5. log 3 6 ⫹ log 3 13.5
6. log 4 32 ⫹ log 4 128
Express as a single logarithm. Simplify, if possible.
7. log 2 80 ⫺ log2 10
10. log 2 1920 ⫺ log 2 30
8. log 10 4000 ⫺ log 10 40
9. log 4 384 ⫺ log 4 6
11. log 3 486 ⫺ log 3 2
12. log 6 180 ⫺ log 6 5
6
13. log 4 4
14. log 5 5 x ⫺ 5
15. 7 log
16. 12 log
17. log 8 8 5
18. log 3 9 4
20. log 3 30
21. log 5 10
Simplify, if possible.
12
1
7
30
Evaluate.
19. log 12 1
Solve.
22. The Richter magnitude of an earthquake, M, is related to the
E .
2 log _____
energy released in ergs, E, by the formula M ⫽ __
3
10 11.8
Find the energy released by an earthquake of magnitude 4.2.
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
a207c07-4_pr_TX.indd 52
52
Holt Algebra 2
3/23/06 8:38:22 AM
Name
T E K S 2A.2.A
LESSON
7-4
Date
Class
Practice B
Properties of Logarithms
Express as a single logarithm. Simplify, if possible.
1. log 3 9 ⫹ log 3 27
log 3 243 ⫽ 5
4. log 6 8 ⫹ log 6 27
log 6 216 ⫽ 3
2. log 2 8 ⫹ log 2 16
3. log 10 80 ⫹ log 10 125
log 2 128 ⫽ 7
log 10 10,000 ⫽ 4
5. log 3 6 ⫹ log 3 13.5
6. log 4 32 ⫹ log 4 128
log 3 81 ⫽ 4
log 4 4096 ⫽ 6
Express as a single logarithm. Simplify, if possible.
7. log 2 80 ⫺ log2 10
log 2 8 ⫽ 3
10. log 2 1920 ⫺ log 2 30
log 2 64 ⫽ 6
8. log 10 4000 ⫺ log 10 40
9. log 4 384 ⫺ log 4 6
log 10 100 ⫽ 2
log 4 64 ⫽ 3
11. log 3 486 ⫺ log 3 2
12. log 6 180 ⫺ log 6 5
log 3 243 ⫽ 5
log 6 36 ⫽ 2
Simplify, if possible.
14. log 5 5 x ⫺ 5
6
13. log 4 4
12
1
7
30
x⫺5
6
16. 12 log
15. 7 log
30
17. log 8 8 5
18. log 3 9 4
1
5
8
Evaluate.
19. log 12 1
20. log 3 30
0
21. log 5 10
3.096
1.43
Solve.
22. The Richter magnitude of an earthquake, M, is related to the
E .
2 log _____
energy released in ergs, E, by the formula M ⫽ __
3
10 11.8
Find the energy released by an earthquake of magnitude 4.2.
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
a207c07-4_pr_TX.indd 52
52
1.26 ⫻ 10 18 ergs
Holt Algebra 2
3/23/06 8:38:22 AM