# Finding x in fraction with scientific notation

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• September 30th 2010, 10:34 AM
msmiley
Finding x in fraction with scientific notation
Hi I need help with this problem...I cant figure it out...help would be appreciated! (Trying to find x)

$\frac{\ 10^8}{10^5} = \frac{\ x}{10^9}$
• September 30th 2010, 11:05 AM
HappyJoe
Do you know your power rules?

You need the rules:

$\frac{10^m}{10^n}=10^{m-n},$
$10^m\cdot 10^n = 10^{m+n}.$

So for example, in your setup, we have

$\frac{10^8}{10^5}=10^{8-5}=10^3.$

And you could multiply both sides of the equation by $10^9$ to get rid of that in the denominator on the right hand side.

Hope this gives you a clue. Otherwise, feel free to ask about troublesome parts.