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For what value of n does StartFraction 216 Superscript n minus 2 Baseline Over (StartFraction 1 Over 36 EndFraction Superscript 3 n?
–3
Negative one-third
Five-ninths
1

2 Answers

3 votes

D. 1 is the answer on edg

User Nico Schuck
by
4.6k points
3 votes

For this case we have the following expression:


\frac {216 ^ {n-2}} {(\frac {1} {36}) ^ {3n}} = 216

We multiply both sides by:
(\frac {1} {36}) ^ {3n}


216 ^ {n-2} = 216 * (\frac {1} {36}) ^ {3n}

We divide both sides by 216:


\frac {216 ^ {n-2}} {216} = (\frac {1} {36}) ^ {3n}

To divide powers of the same base, we place the same base and subtract the exponents:


216 ^ {n-2-1} = (\frac {1} {36}) ^ {3n}\\216 ^ {n-3} = (\frac {1} {36}) ^ {3n}

Rewriting:


(6 ^ 3) ^ {n-3} = (\frac {1} {6 ^ 2}) ^ {3n}\\6 ^ {3n-9} = \frac {1} {6 ^ {6n}}\\6^( 3n-9) * 6^( 6n) = 1

To multiply powers of the same base, we place the same base and add the exponents:


6^( 3n-9 + 6n) = 1\\6^( 9n-9) = 1

We know that any number raised to zero is 1,
a ^ 0 = 1.

So, for equality to be true:


9n-9 = 0\\9n = 9\\n = \frac {9} {9}\\n = 1

Answer:


n = 1

User Hugo Nava Kopp
by
4.2k points