college algebra
posted by tara .
if you have a problem where you are multiplying numbers with exponents (both positive and negative) and your answer ends up with a negative exponent what is the reason you make a fraction out of it and put it on the bottom as a positive?
why cant you have a negative exponent in an answer?

You are right. You can write the answer either way.
For example, if a and b are both positive,
x^a*x^b = x^(ab) or 1/x^(ba) 
but why cant there be a neg. on top? why do u move it to the bottom and make it positive?(note:neg6,5,2 and 4 are exponents)
(4a6b5)(7a2b4)= 28a5b9
the final answer will be 28b9
over
a5
my question was why do you move the "a" negative 5 to the bottom and make it a postive "a" 5
I hope i'm wording this right. 
You can. Just move the exponent up or down between numerator and denominator and change the sign. It's the same number either way.