Which expressions are equivalent to


\[\dfrac{2^5}{6^5}\] ?
Choose 2 answers:
Choose 2 answers:
(Choice A)

\[\dfrac{1}{3}\]
A

\[\dfrac{1}{3}\]
(Choice B)
\[3^{-5}\]
B
\[3^{-5}\]
(Choice C)
\[(-4)^{-5}\]
C
\[(-4)^{-5}\]
(Choice D)
\[2^5\cdot 6^{-5}\]
D
\[2^5\cdot 6^{-5}\]

1 answer

To simplify the expression \(\dfrac{2^5}{6^5}\), we can use the property of exponents to rewrite the denominator:

\[ \dfrac{2^5}{6^5} = 2^5 \cdot (6^{-5}) = 2^5 \cdot 6^{-5} \]

So, option D is equivalent to \(\dfrac{2^5}{6^5}\).

Next, we can express \(6\) in terms of its prime factors:

\[ 6 = 2 \cdot 3 \]

Thus,

\[ 6^5 = (2 \cdot 3)^5 = 2^5 \cdot 3^5 \]

Now, substituting this back into our expression:

\[ \dfrac{2^5}{6^5} = \dfrac{2^5}{2^5 \cdot 3^5} \]

This simplifies to:

\[ \dfrac{1}{3^5} = 3^{-5} \]

So, option B is also equivalent to \(\dfrac{2^5}{6^5}\).

Now we can summarize our findings:

  • Option A: \(\dfrac{1}{3}\) is NOT correct because \(\dfrac{2^5}{6^5} = 3^{-5}\), not \(\dfrac{1}{3}\).
  • Option B: \(3^{-5}\) is correct.
  • Option C: \((-4)^{-5}\) is NOT a correct equivalence, because it is not related to the expression we started with.
  • Option D: \(2^5 \cdot 6^{-5}\) is correct.

Thus, the two correct answers are:

  • (Choice B) \(3^{-5}\)
  • (Choice D) \(2^5 \cdot 6^{-5}\)