Which expression is equivalent to [tex]\left(\frac{a^{-8} b}{a^{-5} b^3}\right)^{-3}[/tex]? Assume [tex]a \neq 0, b \neq 0[/tex].

A. [tex]a^9 b^6[/tex]
B. [tex]a^9 b^{12}[/tex]
C. [tex]\frac{1}{a^3 b^2}[/tex]
D. [tex]\frac{a^{29}}{b^6}[/tex]



Answer :

To simplify the given expression [tex]\(\left(\frac{a^{-8} b}{a^{-5} b^3}\right)^{-3}\)[/tex], we'll go through the steps methodically:

1. Simplify the inner fraction:
[tex]\[ \frac{a^{-8} b}{a^{-5} b^3} \][/tex]

We can separate this into two fractions:
[tex]\[ \frac{a^{-8}}{a^{-5}} \times \frac{b}{b^3} \][/tex]

2. Simplify each part using exponent rules:

For the [tex]\(a\)[/tex] terms, use the rule [tex]\( \frac{a^m}{a^n} = a^{m-n} \)[/tex]:
[tex]\[ \frac{a^{-8}}{a^{-5}} = a^{-8-(-5)} = a^{-8+5} = a^{-3} \][/tex]

For the [tex]\(b\)[/tex] terms, using the same rule:
[tex]\[ \frac{b}{b^3} = b^{1-3} = b^{-2} \][/tex]

So, the expression simplifies to:
[tex]\[ a^{-3} b^{-2} \][/tex]

3. Apply the outer exponent [tex]\((-3)\)[/tex]:
[tex]\[ \left(a^{-3} b^{-2}\right)^{-3} \][/tex]

Use the power of a power rule [tex]\((x^m)^n = x^{mn}\)[/tex]:
[tex]\[ (a^{-3})^{-3} = a^{-3 \times -3} = a^{9} \][/tex]
[tex]\[ (b^{-2})^{-3} = b^{-2 \times -3} = b^{6} \][/tex]

4. Combine the simplified parts:
[tex]\[ a^9 b^6 \][/tex]

Therefore, the expression [tex]\(\left(\frac{a^{-8} b}{a^{-5} b^3}\right)^{-3}\)[/tex] is equivalent to [tex]\(a^9 b^6\)[/tex].

So the correct answer is:
[tex]\[ \boxed{a^9 b^6} \][/tex]