Answer :

To divide the given expressions, we can rewrite the division as a multiplication by the reciprocal. The given expressions are:

[tex]\[ \frac{5 b}{4 a^2} \div \frac{b^4}{8 a^5 b} \][/tex]

To handle this division, we'll follow these steps:

1. Rewrite the division as multiplication by the reciprocal of the second fraction.

[tex]\[ \frac{5 b}{4 a^2} \times \frac{8 a^5 b}{b^4} \][/tex]

2. Multiply the numerators and the denominators.

[tex]\[ \frac{5 b \cdot 8 a^5 b}{4 a^2 \cdot b^4} \][/tex]

3. Combine the numerators and the denominators.

[tex]\[ \frac{40 b^2 a^5}{4 a^2 b^4} \][/tex]

4. Simplify the fraction by dividing the numerator and the denominator by their common factors.

- For the coefficients, divide 40 by 4:

[tex]\[ \frac{40}{4} = 10 \][/tex]

- For the [tex]\( b \)[/tex]-terms: [tex]\( b^2 \)[/tex] in the numerator and [tex]\( b^4 \)[/tex] in the denominator, subtract the exponents (since [tex]\( b^4 \)[/tex] in the denominator can be written as [tex]\( \frac{1}{b^4} \)[/tex] when the property of exponents [tex]\( \frac{b^m}{b^n} = b^{m-n} \)[/tex] is applied):

[tex]\[ b^{2-4} = b^{-2} = \frac{1}{b^2} \][/tex]

- For the [tex]\( a \)[/tex]-terms: [tex]\( a^5 \)[/tex] in the numerator and [tex]\( a^2 \)[/tex] in the denominator, subtract the exponents:

[tex]\[ a^{5-2} = a^3 \][/tex]

5. Combine these simplified terms:

[tex]\[ 10 \times \frac{a^3}{b^2} \][/tex]

Thus, the simplified form of the division is:

[tex]\[ \frac{10 a^3}{b^2} \][/tex]

This is the final simplified result.