Which expression is equivalent to [tex]\left(\frac{\left(2 a^{-3} b^4\right)^2}{\left(3 a^5 b\right)^{-2}}\right)^{-1}[/tex]? Assume [tex]a \neq 0[/tex], [tex]b \neq 0[/tex].

A. [tex]\frac{2}{3 a^4 b^{10}}[/tex]
B. [tex]\frac{4}{9 a^4 b^{10}}[/tex]
C. [tex]\frac{1}{36 a^4 b^{10}}[/tex]
D. [tex]\frac{36 a^4 b^{10}}{2}[/tex]



Answer :

Let's simplify the given expression step by step:

The given expression is
[tex]\[ \left(\frac{\left(2 a^{-3} b^4\right)^2}{\left(3 a^5 b\right)^{-2}}\right)^{-1} \][/tex]

### Step 1: Simplify the Numerator
First, we simplify [tex]\((2 a^{-3} b^4)^2\)[/tex]:

[tex]\[ (2 a^{-3} b^4)^2 = 2^2 \cdot (a^{-3})^2 \cdot (b^4)^2 \][/tex]

Applying the powers, we get:

[tex]\[ 2^2 = 4, \quad (a^{-3})^2 = a^{-6}, \quad (b^4)^2 = b^8 \][/tex]

Thus, the numerator becomes:

[tex]\[ 4 a^{-6} b^8 \][/tex]

### Step 2: Simplify the Denominator
Next, simplify [tex]\((3 a^5 b)^{-2}\)[/tex]:

[tex]\[ (3 a^5 b)^{-2} = 3^{-2} \cdot (a^5)^{-2} \cdot (b)^{-2} \][/tex]

Applying the powers, we get:

[tex]\[ 3^{-2} = \frac{1}{9}, \quad (a^5)^{-2} = a^{-10}, \quad b^{-2} \][/tex]

Thus, the denominator becomes:

[tex]\[ \frac{1}{9} a^{-10} b^{-2} \][/tex]

### Step 3: Combine the Simplified Numerator and Denominator
Next, we combine the simplified numerator and denominator:

[tex]\[ \left(\frac{4 a^{-6} b^8}{\frac{1}{9} a^{-10} b^{-2}}\right) \][/tex]

Simplify the division:

[tex]\[ \frac{4 a^{-6} b^8}{\frac{1}{9} a^{-10} b^{-2}} = \frac{4 a^{-6} b^8 \cdot 9}{a^{-10} b^{-2}} = 4 \cdot 9 \cdot \frac{a^{-6}}{a^{-10}} \cdot \frac{b^8}{b^{-2}} \][/tex]

This simplifies to:

[tex]\[ 36 \cdot a^{-6 - (-10)} \cdot b^{8 - (-2)} = 36 \cdot a^4 \cdot b^{10} \][/tex]

### Step 4: Apply the Power of -1 to the Simplified Expression
Next, we apply the power of -1:

[tex]\[ \left(36 a^4 b^{10}\right)^{-1} = \frac{1}{36 a^4 b^{10}} \][/tex]

### Conclusion
The given multiple-choice answers are:
- [tex]\(\frac{2}{3 a^4 b^{10}}\)[/tex]
- [tex]\(\frac{4}{9 a^4 b^{10}}\)[/tex]
- [tex]\(\frac{1}{36 a^4 b^{10}}\)[/tex]
- [tex]\(\frac{36 a^4 b^{10}}{2}\)[/tex]

The correct equivalent expression is:

[tex]\[ \boxed{\frac{1}{36 a^4 b^{10}}} \][/tex]