Simplify Expressions 733B29
1. **Problem:** Simplify the expression $a (5x^2)^3$.
2. **Formula:** Use the power of a product rule: $(ab)^n = a^n b^n$ and the power of a power rule: $(x^m)^n = x^{mn}$.
3. **Step-by-step:**
- Expand $(5x^2)^3 = 5^3 (x^2)^3 = 125 x^{6}$.
- Multiply by $a$: $a imes 125 x^{6} = 125 a x^{6}$.
4. **Answer:** The simplified form is $125 a x^{6}$.
---
5. **Problem:** Simplify $(16x^4)^{1/2}$.
6. **Formula:** Use the rule $(a^m)^{n} = a^{mn}$ and the square root as power $1/2$.
7. **Step-by-step:**
- $(16x^4)^{1/2} = 16^{1/2} imes (x^4)^{1/2} = 4 imes x^{2} = 4 x^{2}$.
8. **Answer:** The simplified form is $4 x^{2}$.
---
9. **Problem:** Simplify $(64x^9)^{1/3}$.
10. **Formula:** Use cube root as power $1/3$.
11. **Step-by-step:**
- $(64x^9)^{1/3} = 64^{1/3} imes (x^9)^{1/3} = 4 imes x^{3} = 4 x^{3}$.
12. **Answer:** The simplified form is $4 x^{3}$.
---
13. **Problem:** Matin has 7 number cards with positive numbers. Five cards are [9], [13], [4], [10], [7]. The range is 16 and the mode is 9. Find the two missing numbers.
14. **Formula:** Range = max - min; Mode is the most frequent number.
15. **Step-by-step:**
- Known numbers: 4, 7, 9, 10, 13.
- Range = 16 means max - min = 16.
- Min is 4 (lowest known), so max = 4 + 16 = 20.
- Mode is 9, so 9 must appear more than once.
- Currently, 9 appears once; to be mode, at least one more 9 is needed.
- Two missing numbers: one is 9 (to make mode), the other is 20 (to make range).
16. **Answer:** The missing numbers are 9 and 20.
---
17. **Problem:** Find $x$ in $2^{x+1} = 8^2$.
18. **Formula:** Express both sides with the same base.
19. **Step-by-step:**
- $8 = 2^3$, so $8^2 = (2^3)^2 = 2^{6}$.
- Equation: $2^{x+1} = 2^{6}$.
- Equate exponents: $x + 1 = 6$.
- Solve: $x = 5$.
20. **Answer:** $x = 5$.
---
21. **Problem:** Find $x$ in $3^{x - 2/5} = rac{1}{81}$.
22. **Formula:** Express right side as power of 3.
23. **Step-by-step:**
- $81 = 3^4$, so $1/81 = 3^{-4}$.
- Equation: $3^{x - 2/5} = 3^{-4}$.
- Equate exponents: $x - rac{2}{5} = -4$.
- Solve: $x = -4 + rac{2}{5} = -rac{20}{5} + rac{2}{5} = -rac{18}{5}$.
24. **Answer:** $x = -rac{18}{5}$.
---
25. **Problem:** Solve $\\sqrt{\frac{11}{25}}$.
26. **Formula:** $\\sqrt{\frac{a}{b}} = rac{\sqrt{a}}{\sqrt{b}}$.
27. **Step-by-step:**
- $\\sqrt{\frac{11}{25}} = rac{\sqrt{11}}{5}$.
28. **Answer:** $rac{\sqrt{11}}{5}$.
---
29. **Problem:** Simplify $4x^3 y^2 \times 3x^2 y$.
30. **Formula:** Multiply coefficients and add exponents of like bases.
31. **Step-by-step:**
- Coefficients: $4 \times 3 = 12$.
- $x^{3} \times x^{2} = x^{5}$.
- $y^{2} \times y^{1} = y^{3}$.
- Result: $12 x^{5} y^{3}$.
32. **Answer:** $12 x^{5} y^{3}$.
---
33. **Problem:** Simplify $(\frac{4}{5} + \frac{y}{7}) \times \frac{3}{2}$.
34. **Formula:** Distribute multiplication over addition.
35. **Step-by-step:**
- Multiply each term by $\frac{3}{2}$:
- $\frac{4}{5} \times \frac{3}{2} = \frac{12}{10} = \frac{6}{5}$.
- $\frac{y}{7} \times \frac{3}{2} = \frac{3y}{14}$.
- Result: $\frac{6}{5} + \frac{3y}{14}$.
36. **Answer:** $\frac{6}{5} + \frac{3y}{14}$.