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please look at the picture! answer needed quick, "which expression is NOT equal to the expression shown?"

please look at the picture! answer needed quick, "which expression is NOT equal-example-1

1 Answer

2 votes
Exponents

We know that the negative exponents exchange the order of the fraction. For example,


(1)/(3^(-4))=3^4

If the exponent 4 was negative down, when it is up it is positive.

Then,


(3^3)/(3^(-4))=3^3\cdot3^4

When two exponents with the same base are multiplying their exponents are added, then


3^3\cdot3^4=3^(3+4)=3^7

when one is the dividing the other, their exponents are subtracted:


(3^3)/(3^(-4))=3^(3-(-4))=3^(3+4)=3^7

In all the options we have 3⁷:


\begin{gathered} (3^7)/(3^0)=3^(7-0)=3^7 \\ 3^3\cdot3^4=3^(3+4)=3^7 \\ 3\cdot3^6=3^(1+6)=3^7 \end{gathered}

But, for the first option:


(3^(-3))/(3^4)=3^(-3-4)=3^(-7)

Then, the only option that is not equal is the first

Answer: A

User Kyle Grage
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