Trouble with negative exponents

[ARubio75]

Hi. I'm having trouble figuring out an exponential equation. I don't know how to type it correctly here but I'll do my best:

2.5 x 10 to the -5 divided by 4.0 x 10 to the -10

 

[wjm11]

2.5 x 10 to the -5 divided by 4.0 x 10 to the –10

Here is one way to write it:
(2.5)(10^(-5))/[4(10^(-10))]

Since this is all multiplication and division, we can rearrange things in a way to make them more understandable. (We are allowed to rearrange things because of the commutative property of multiplication, which says that ab = ba. Make sense?)

So think of the problem as

(2.5/4)[(10^(-5)/(10^(-10))]
= .625(10^5)

Or, putting the answer into proper scientific notation:

6.25 x 10^4

 

[Denis]

REMEMBER that a^x / a^(-y) = a^(x+y)