[tex]\[
\left(\frac{8^{-5}}{2^{-2}}\right)^{-4} = ?
\][/tex]

Choose 1 answer:

A. [tex]\(\frac{1}{8 \cdot 2^2}\)[/tex]

B. [tex]\(\frac{2^6}{8^9}\)[/tex]

C. [tex]\(\frac{8^{20}}{2^8}\)[/tex]



Answer :

The problem requires simplifying the expression [tex]\(\left(\frac{8^{-5}}{2^{-2}}\right)^{-4}\)[/tex].

Let's break it down step-by-step.

### Step 1: Simplify the Inner Expression
First, let's focus on the expression inside the parentheses:

[tex]\[ \frac{8^{-5}}{2^{-2}} \][/tex]

Notice that [tex]\(8\)[/tex] can be written as [tex]\(2^3\)[/tex]:

[tex]\[ 8^{-5} = (2^3)^{-5} = 2^{-15} \][/tex]

Thus, the inner expression becomes:

[tex]\[ \frac{2^{-15}}{2^{-2}} \][/tex]

### Step 2: Simplify the Division of Exponents
When dividing powers with the same base, we subtract the exponents:

[tex]\[ 2^{-15} / 2^{-2} = 2^{-15 - (-2)} = 2^{-15 + 2} = 2^{-13} \][/tex]

### Step 3: Apply the Outer Exponent
Now, we need to raise the simplified inner expression to the power of [tex]\(-4\)[/tex]:

[tex]\[ (2^{-13})^{-4} \][/tex]

When raising a power to another power, we multiply the exponents:

[tex]\[ 2^{-13 \cdot (-4)} = 2^{52} \][/tex]

### Step 4: Compare to Given Options
Our expression simplifies to [tex]\(2^{52}\)[/tex].

Now let's compare this with the given options.

#### Option (A)
[tex]\[ \frac{1}{8 \cdot 2^2} = \frac{1}{8 \cdot 4} = \frac{1}{32} \][/tex]

Clearly, [tex]\(\frac{1}{32}\)[/tex] is not equal to [tex]\(2^{52}\)[/tex].

#### Option (B)
[tex]\[ \frac{2^6}{8^9} \][/tex]

Let's convert [tex]\(8^9\)[/tex] to base 2:
[tex]\[ 8^9 = (2^3)^9 = 2^{27} \][/tex]
Thus,
[tex]\[ \frac{2^6}{2^{27}} = 2^{6-27} = 2^{-21} \][/tex]

Clearly, [tex]\(2^{-21}\)[/tex] is not equal to [tex]\(2^{52}\)[/tex].

#### Option (C)
[tex]\[ \frac{8^{20}}{2^8} \][/tex]

Convert [tex]\(8^{20}\)[/tex] to base 2:
[tex]\[ 8^{20} = (2^3)^{20} = 2^{60} \][/tex]

So,
[tex]\[ \frac{2^{60}}{2^8} = 2^{60-8} = 2^{52} \][/tex]

This matches our simplified result [tex]\(2^{52}\)[/tex].

### Conclusion
The correct option is:

[tex]\[ \boxed{\text{C} \ \frac{8^{20}}{2^8}} \][/tex]