Find the equivalent exponential expression.

12^-28

A.(12^-7)^4
B.(12^-7)^21
C.(12^-7)^-21
D.(12)^-29

Question

Find the equivalent exponential expression. 

12^-28

A.(12^-7)^4
B.(12^-7)^21
C.(12^-7)^-21
D.(12)^-29

solomonzelman · Answer

$\Large\color{black}{ \bf   a^{-b}=\frac{1}{a^{b}}    }$

anonymous · Answer

Care to explain how to use that formula?

imstuck · Answer

Actually you need to use the fact that$$(x ^{a})^{b}=x ^{ab}$$so the first choice is your answer because $$(12^{-7})^{4}=12^{(-7)(4)}=12^{-28}$$

solomonzelman · Answer

$\Large\color{black}{ \bf   12^{-28}=\frac{1}{12^{28}} =?   }$

anonymous · Answer

Thank you IMStuck for very much so clarifying and using the right formula! :)

imstuck · Answer

Although SolomonZelman is correct in the general sense, I do not believe that they are asking you to rid yourself of the negative exponent in this case.