SOLUTION: I am working on exponents and have a couple of questions. 1) Solve -r^-2 if r=-3 I know the answer is -1/9 but I don't understand why it is a negative. I thought the negative s

Algebra ->  Exponents-negative-and-fractional -> SOLUTION: I am working on exponents and have a couple of questions. 1) Solve -r^-2 if r=-3 I know the answer is -1/9 but I don't understand why it is a negative. I thought the negative s      Log On


   

Question 427789: I am working on exponents and have a couple of questions.
1) Solve -r^-2 if r=-3
I know the answer is -1/9 but I don't understand why it is a negative. I thought the negative symbol in the problem and the negative symbol on the 3 would cancel each other out and make it a positive.
2) What is the difference between the following three probs. I am just not understanding what to do about the - sign and when to do it!
-5^-3
(-5)^-3
-(5)^3
I was not sure how to show the exponents and someone told me to use the ^ symbol so I did. Hope it makes sense. I am stuck!!
Thank you.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1) Solve -r^-2 if r=-3
Replace r with -3 and write it like this in your calc:
-(-3)^-2, you will get -.1111 which is -1%2F9
Because if you thought of it as
-(1%2F-3*1%2F-3) = -(1%2F9)
:
2) What is the difference between the following three probs. I am just not understanding what to do about the - sign and when to do it!
-5^-3
(-5)^-3
-(5)^3
:
There is no difference in the first two, enter each like it is written into your calc, they will all give the same result, that last one will = -125