Which of these equations is correct?

A. (2^2)^4 = 2^6

B. (3^5)^-2 = 1/3^-10

C. (5^-3)^6 = 1/5^18

D. (8^3)^2 = 8^9

1 answer

Let's evaluate each equation one by one to determine which one is correct.

A. \((2^2)^4 = 2^6\)

Using the power of a power property \((a^m)^n = a^{mn}\):

\[ (2^2)^4 = 2^{2 \cdot 4} = 2^8 \]

So, the left side becomes \(2^8\), and the right side is \(2^6\).

This is incorrect since \(2^8 \neq 2^6\).


B. \((3^5)^{-2} = 1/3^{-10}\)

Starting with the left side:

\[ (3^5)^{-2} = 3^{5 \cdot -2} = 3^{-10} \]

For the right side, using \(1/a^{-n} = a^n\):

\[ 1/3^{-10} = 3^{10} \]

This means \(3^{-10} \neq 3^{10}\).

This is incorrect since \(3^{-10} \neq 3^{10}\).


C. \((5^{-3})^6 = 1/5^{18}\)

Evaluating the left side:

\[ (5^{-3})^6 = 5^{-3 \cdot 6} = 5^{-18} \]

For the right side, we use the property of exponents:

\[ 1/5^{18} = 5^{-18} \]

So, we have \(5^{-18} = 5^{-18}\).

This is correct.


D. \((8^3)^2 = 8^9\)

Using the power of a power property again:

\[ (8^3)^2 = 8^{3 \cdot 2} = 8^6 \]

So, the left side becomes \(8^6\) and the right side is \(8^9\).

This is incorrect since \(8^6 \neq 8^9\).


The correct equation is C. \((5^{-3})^6 = 1/5^{18}\).