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how do u simplify a fraction with a denominator of 2^-3?

 May 29, 2015

Best Answer 

 #1
avatar+980 
+10

For example:

 

$${\frac{{\mathtt{x}}}{{{\mathtt{2}}}^{-{\mathtt{3}}}}}$$

 

$${\frac{{\mathtt{x}}}{\left({\frac{{\mathtt{1}}}{{{\mathtt{2}}}^{{\mathtt{3}}}}}\right)}}$$

 

$$\left({\frac{{\mathtt{x}}}{{\mathtt{1}}}}\right){\mathtt{\,\times\,}}\left({\frac{\left({{\mathtt{2}}}^{{\mathtt{3}}}\right)}{{\mathtt{1}}}}\right)$$

 

$${{\mathtt{2}}}^{{\mathtt{3}}}{\mathtt{\,\times\,}}{\mathtt{x}}$$

 May 29, 2015
 #1
avatar+980 
+10
Best Answer

For example:

 

$${\frac{{\mathtt{x}}}{{{\mathtt{2}}}^{-{\mathtt{3}}}}}$$

 

$${\frac{{\mathtt{x}}}{\left({\frac{{\mathtt{1}}}{{{\mathtt{2}}}^{{\mathtt{3}}}}}\right)}}$$

 

$$\left({\frac{{\mathtt{x}}}{{\mathtt{1}}}}\right){\mathtt{\,\times\,}}\left({\frac{\left({{\mathtt{2}}}^{{\mathtt{3}}}\right)}{{\mathtt{1}}}}\right)$$

 

$${{\mathtt{2}}}^{{\mathtt{3}}}{\mathtt{\,\times\,}}{\mathtt{x}}$$

zacismyname May 29, 2015
 #2
avatar+118587 
+5

Hi Zac,

you always get these correct but you do not need to make them looks so complicated.

$$\\2^{-3}=\frac{2^{-3}}{1}\\\\
$Now anything raised to a neg power gets swapped to the other side of the fraction line, and anything not raised to a negative power stays where it is$\\\\
$So the 1 stays , the $2^{-3}$ goes to the other side of the fraction line and the - becomes a +. $\\\\
$There is nothing on the top any more so just put a 1 there$\\\\
\frac{2^{-3}}{1}=\frac{?}{1*2^{+3}}=\frac{1}{2^{3}}\\\\$$

 

Once you do a couple you wil see that it is heaps easier.   

 May 29, 2015
 #3
avatar+118587 
+8

Oh I did not do the correct question  

 

$$\frac{x}{2^{-3}}=\frac{x*2^{+3}}{1}=8x$$

 May 29, 2015
 #4
avatar+980 
+5

Well I like to show the in-between steps because I think it makes it easier to understand but once you know the rule you can just cut straight to the answer.

 May 29, 2015
 #5
avatar+118587 
+3

Oh, ok fair enough.  I teach it without the steps inbetween :)

 May 29, 2015

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