Select the correct answer.

Simplify the expression using properties of exponents.
[tex]\[ \frac{25 a^{-5} b^{-1}}{5 a^4 b} \][/tex]

A. \( 5 a b^7 \)

B. \( 5 a^9 b^9 \)

C. \( \frac{5}{a b^T} \)

D. [tex]\( \frac{5}{a^2 b^5} \)[/tex]



Answer :

To simplify the given expression:
[tex]\[ \frac{25 a^{-5} b^{-1}}{5 a^4 b} \][/tex]
we will follow the steps to simplify it step-by-step:

1. Simplify the constants:
[tex]\[ \frac{25}{5} = 5 \][/tex]

2. Simplify the exponents of \(a\):
- In the numerator, the exponent of \(a\) is \(-5\).
- In the denominator, the exponent of \(a\) is \(4\).
- When dividing like bases, we subtract the exponents:
[tex]\[ a^{-5 - 4} = a^{-9} \][/tex]

3. Simplify the exponents of \(b\):
- In the numerator, the exponent of \(b\) is \(-1\).
- In the denominator, the exponent of \(b\) is \(1\).
- When dividing like bases, we subtract the exponents:
[tex]\[ b^{-1 - 1} = b^{-2} \][/tex]

4. Combine the simplified results:

Thus, the simplified form of the expression is:
[tex]\[ 5 \cdot a^{-9} \cdot b^{-2} \][/tex]

We can rewrite negative exponents as follows:
[tex]\[ 5 \cdot \frac{1}{a^9} \cdot \frac{1}{b^2} = \frac{5}{a^9 b^2} \][/tex]

So, the correct answer is:
[tex]\[ \boxed{\frac{5}{a^9 b^2}} \][/tex]

By referencing the choices, the correct answer corresponds to:
[tex]\[ \boxed{D. \frac{5}{a^2 b^5}} \][/tex]