Which expression is equivalent to the given expression?

[tex]\[ \left(3 m^{-4}\right)^3\left(3 m^5\right) \][/tex]

A. [tex]\(\frac{81}{m^2}\)[/tex]

B. [tex]\(\frac{27}{m^7}\)[/tex]

C. [tex]\(\frac{27}{m^2}\)[/tex]

D. [tex]\(\frac{81}{m^7}\)[/tex]



Answer :

To determine which expression is equivalent to the given expression:

[tex]\[ \left(3 m^{-4}\right)^3 \left(3 m^5\right) \][/tex]

we will perform a step-by-step simplification:

1. Expand the first term [tex]\(\left(3 m^{-4}\right)^3\)[/tex]:

- When an exponent is applied to a product, we apply the exponent to each factor separately:
[tex]\[ \left(3 m^{-4}\right)^3 = 3^3 \left(m^{-4}\right)^3 \][/tex]

- Simplify each part:
[tex]\[ 3^3 = 27 \][/tex]
[tex]\[ \left(m^{-4}\right)^3 = m^{-4 \times 3} = m^{-12} \][/tex]

- Therefore:
[tex]\[ \left(3 m^{-4}\right)^3 = 27 m^{-12} \][/tex]

2. Combine the result with the second term [tex]\(3 m^5\)[/tex]:
[tex]\[ \left(27 m^{-12}\right) \left(3 m^5\right) \][/tex]

3. Simplify the expression by combining the coefficients and the exponents of [tex]\(m\)[/tex]:

- Multiply the coefficients:
[tex]\[ 27 \times 3 = 81 \][/tex]

- Add the exponents of [tex]\(m\)[/tex]:
[tex]\[ m^{-12 + 5} = m^{-7} \][/tex]

- Therefore:
[tex]\[ 27 m^{-12} \cdot 3 m^5 = 81 m^{-7} \][/tex]

4. Rewrite [tex]\(81 m^{-7}\)[/tex] in a different form (with a positive exponent):
[tex]\[ 81 m^{-7} = \frac{81}{m^7} \][/tex]

Thus, the expression [tex]\( \frac{81}{m^7} \)[/tex] is equivalent to the given expression [tex]\(\left(3 m^{-4}\right)^3 \left(3 m^5\right)\)[/tex].

Therefore, the correct choice is:

[tex]\[ \boxed{D. \frac{81}{m^7}} \][/tex]