Simplify Powers 362F6D
1. State the problem: Simplify each expression.
2. The three expressions to simplify are: a) $ (5x^2)^3 $.
3. b) $ (16x^4)^{1/4} $.
4. c) $ (64x^9)^{1/3} $.
5. Formula and rules used: the power rules are
$$ (ab)^n = a^n b^n $$
and
$$ (a^m)^n = a^{mn} $$
These allow us to raise each factor to the outer exponent.
6. Important rule about even roots: when an even root is taken as a principal root, the result is nonnegative, so $ (x^4)^{1/4} = |x| $ for real $x$.
7. Work for (a): Apply the rule $ (a^m)^n = a^{mn} $ to each factor.
8. $ (5x^2)^3 = 5^3 \cdot (x^2)^3 $.
9. $ 5^3 = 125 $ and $ (x^2)^3 = x^{2\cdot 3} = x^6 $.
10. Therefore $ (5x^2)^3 = 125x^6 $.
11. Work for (b): Distribute the exponent $1/4$ to each factor.
12. $ (16x^4)^{1/4} = 16^{1/4} \cdot (x^4)^{1/4} $.
13. $ 16^{1/4} = 2 $ because $2^4 = 16$.
14. For the $x$ part, $ (x^4)^{1/4} = |x| $ as explained above because the fourth root is an even principal root.
15. Therefore the principal real value is $ (16x^4)^{1/4} = 2|x| $.
16. (If you assume $x\ge 0$ you can write the simplified form as $2x$.)
17. Work for (c): Distribute the exponent $1/3$ to each factor.
18. $ (64x^9)^{1/3} = 64^{1/3} \cdot (x^9)^{1/3} $.
19. $ 64^{1/3} = 4 $ because $4^3 = 64$.
20. $ (x^9)^{1/3} = x^{9\cdot(1/3)} = x^3 $ and no absolute value is required because cube roots are odd-indexed.
21. Therefore $ (64x^9)^{1/3} = 4x^3 $.
22. Final answers:
23. a) $125x^6$.
24. b) $2|x|$ (or $2x$ if $x\ge 0$).
25. c) $4x^3$.