If $$3^{-a}=2$$ Evaluate $$3^{a-1} $$
Here's my attempt:
$$3^{-a}=2$$
Rewriting the equation
$$3^{a}=2^{-1} \implies 3^{a-1} = 2^{-2} = \dfrac 1 4$$
Regards!
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you were almost there ...just multiply both side by 1/3 – user577215664 Jul 31 '18 at 12:25
2 Answers
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Not quite
If $3^{a}=2^{-1}$
then you need to divide both sides by $3$
to get $3^{a-1}$ on the left hand side
and the answer on the right hand side
Henry
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Where can I find similiar examples on textbooks? I've recently taken a look at an algebra book. However, I couldn't find anything useful. – Maxwell Jul 31 '18 at 12:25
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You were almost there $$3^{a}=2^{-1} \implies 3^{a-1} = 2^{-2} = \dfrac 1 4$$ note that $$3^{a-1}=3^a \times 3^{-1}= \frac {3^a}3= {3^a}\times \frac 13$$ So multiply both side by 1/3
user577215664
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@Maxwell you don't need that here...you did almost all the job except for the last step – user577215664 Jul 31 '18 at 12:32
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How do I need to search it on textbooks in order to find similar examples? I couldn't see any. – Maxwell Jul 31 '18 at 12:33
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@maxwell try google search "exercices solutions fractions power " ...you should find what you need...that's what I do when I need specific exercices – user577215664 Jul 31 '18 at 12:44