SOLUTION: im having trouble figureing out these sorts of problems ive donw really good in math up until algebra 2 and now im stuck how do you take the 3rd root of -125

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Question 29083: im having trouble figureing out these sorts of problems ive donw really good in math up until algebra 2 and now im stuck how do you take the 3rd root of -125
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Find:
%28-125%29%5E%281%2F3%29 So you are really looking for a number n, such thatn%5E3+=+-125
You try can factoring -125. But you want the factors to be identical, so start with +125.
You know 125 divides by 5 because its one's position is 5, so:
5(25) = 125 Now factor the 25 to get 5*5.
So, now you have 5*5*5 = 125 A good start, but you really want to get -125, try (-5)(-5)(-5) = -125 Aha! So:
%28-125%29%5E%281%2F3%29+=+%28%28-5%29%28-5%29%28-5%29%29%5E%281%2F3%29 = %28%28-5%29%5E3%29%5E%281%2F3%29 = -5
The third root of -125 = -5