algebra exponents

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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algebra exponents

by Joka74 » Thu Dec 13, 2012 4:59 pm
Negative Exponent Rule for Exponents:
Negative exponents and negative numbers have nothing whatsoever to do with each other - and they don't mingle well. A negative number is a number that belongs to the left of the zero on the number line. A negative exponent is mathematical shorthand for "you and your base should be on the other side of the fraction bar, with a positive exponent. The official rule for negative exponents is this:
a -m = 1 over a m , or , in the more complete version, a -m over b -n = b n over a m

Let's change the first formula so you see the term a -m written as a fraction:
a -m over 1 and the negative exponent means "hey, you are just an a with a positive m exponent that belongs on the other side of the fraction bar - move to the denominator, change your exponent to positive, multiply yourself to whoever is already there, and replace yourself in the numerator with a 1.

can anyone explain to me why you flip it and multiply it or put a 1? where does the b go or what happen to it?? im trying to figure out why it is done this way?? i copied and pasted but it didnt take the examples with it for some reason so i wrote them in the best i could. it uses a and b as a fraction the a has a negative m exponent and the b has a negative n for an exponent. none of this really makes sense to me and idk why.
Source: — Quantitative Reasoning |

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by Jim@StratusPrep » Fri Dec 14, 2012 6:06 am
Not sure I quite understand your question, but here is one of the best ways to reconcile this issue:


x^-1 = 1/x^1 = x^0/x^1 = x^(0-1) = x^-1

Remember that anything raised to a 0 power equals 1.
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by Joka74 » Fri Dec 14, 2012 2:27 pm
i think this might help but i dont understand what that means... can i get you to explain what you just did and why?? and how does 0 equal one??

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by gander123 » Wed Dec 19, 2012 2:34 pm
Hey Joka,

Please note the following:

One of our exponent rules holds that x^y / x^n = x^(y-n). If you set y=n, x is raised to the power of something and then devided by x raised to the power of the same "something". In other words, the numerator is equal to the denominator. Anything devided by itself will always yield 1, be it a/a , b/b or 100/100.

HTH

kind regards,

Tobi