Let's solve each logarithmic expression step by step using logarithmic properties and basic exponent rules.
---
Logarithm Basics:
Recall:
- $\log_b(b) = 1$
- $\log_b(1) = 0$ for any base $b > 0$, $b \ne 1$
- $\log_b(a^n) = n \cdot \log_b(a)$
- $\log_b\left(\frac{1}{a}\right) = -\log_b(a)$
- If $b^x = a$, then $\log_b(a) = x$
---
Now, let’s evaluate each one:
---
1. $\log_7(49)$
$49 = 7^2$, so $\log_7(49) = \log_7(7^2) = 2$
✔ Answer: 2
---
2. $\log_2(32)$
$32 = 2^5$, so $\log_2(32) = \log_2(2^5) = 5$
✔ Answer: 5
---
3. $\log_{12}(1)$
Any log of 1 is 0, since $b^0 = 1$
✔ Answer: 0
---
4. $\log_4\left(\frac{1}{16}\right)$
$\frac{1}{16} = \frac{1}{4^2} = 4^{-2}$, so $\log_4(4^{-2}) = -2$
✔ Answer: -2
---
5. $\log_3(3)$
$\log_b(b) = 1$, so this is 1
✔ Answer: 1
---
6. $\log_4(16)$
$16 = 4^2$, so $\log_4(16) = \log_4(4^2) = 2$
✔ Answer: 2
---
7. $\log_2\left(\frac{1}{2}\right)$
$\frac{1}{2} = 2^{-1}$, so $\log_2(2^{-1}) = -1$
✔ Answer: -1
---
8. $\log_{10}(100)$
$100 = 10^2$, so $\log_{10}(100) = 2$
✔ Answer: 2
---
9. $\log_4(4)$
$\log_b(b) = 1$, so this is 1
✔ Answer: 1
---
10. $\log_2(2)$
$\log_b(b) = 1$, so this is 1
✔ Answer: 1
---
11. $\log_4(1)$
$\log_b(1) = 0$, so this is 0
✔ Answer: 0
---
12. $\log_3(81)$
$81 = 3^4$, so $\log_3(81) = \log_3(3^4) = 4$
✔ Answer: 4
---
13. $\log_{10}\left(\frac{1}{1000}\right)$
$\frac{1}{1000} = 10^{-3}$, so $\log_{10}(10^{-3}) = -3$
✔ Answer: -3
---
14. $\log_7(7)$
$\log_b(b) = 1$, so this is 1
✔ Answer: 1
---
15. $\log_3(9)$
$9 = 3^2$, so $\log_3(9) = \log_3(3^2) = 2$
✔ Answer: 2
---
16. $\log_7(1)$
$\log_b(1) = 0$, so this is 0
✔ Answer: 0
---
17. $\log_{10}\left(\frac{1}{100}\right)$
$\frac{1}{100} = 10^{-2}$, so $\log_{10}(10^{-2}) = -2$
✔ Answer: -2
---
18. $\log_7\left(\frac{1}{7}\right)$
$\frac{1}{7} = 7^{-1}$, so $\log_7(7^{-1}) = -1$
✔ Answer: -1
---
19. $\log_8(1)$
$\log_b(1) = 0$, so this is 0
✔ Answer: 0
---
20. $\log_7\left(\frac{1}{49}\right)$
$\frac{1}{49} = \frac{1}{7^2} = 7^{-2}$, so $\log_7(7^{-2}) = -2$
✔ Answer: -2
---
✔ Final Answers (in order):
| Expression | Answer |
|----------|--------|
| $\log_7(49)$ |
2 |
| $\log_2(32)$ |
5 |
| $\log_{12}(1)$ |
0 |
| $\log_4\left(\frac{1}{16}\right)$ |
-2 |
| $\log_3(3)$ |
1 |
| $\log_4(16)$ |
2 |
| $\log_2\left(\frac{1}{2}\right)$ |
-1 |
| $\log_{10}(100)$ |
2 |
| $\log_4(4)$ |
1 |
| $\log_2(2)$ |
1 |
| $\log_4(1)$ |
0 |
| $\log_3(81)$ |
4 |
| $\log_{10}\left(\frac{1}{1000}\right)$ |
-3 |
| $\log_7(7)$ |
1 |
| $\log_3(9)$ |
2 |
| $\log_7(1)$ |
0 |
| $\log_{10}\left(\frac{1}{100}\right)$ |
-2 |
| $\log_7\left(\frac{1}{7}\right)$ |
-1 |
| $\log_8(1)$ |
0 |
| $\log_7\left(\frac{1}{49}\right)$ |
-2 |
---
Let me know if you'd like these explained in more detail!
Parent Tip: Review the logic above to help your child master the concept of logarithms worksheet.