Exponents?

Question

i completely forgot the rules when you multiply, subtract, divide and add things with exponents!

okay, when you multiply, say

1.29 x 10^3 x 3 x 10^17

would it be 3.87 x 10^20, or 1.47 x 10^21? i add the exponents right?

and another one:

3 x 10^17
------------- (divided by)
5.4 x 10^5

you subtract right? so...5.5 x 10^11??

thanks a lot!

also, we are calculating the frequency/wavelength of electromagnetic radiation, so our problems are like v= 3 x 10^12 hertz. but the last problem is v = 17 megahertz. how can i solve this? or, how many hertz are in a megahertz?

Answer 1

1.29 x 3 x 10^20; you add 3 and 17

3/5.4 x 10^12; you subtract 5 from 17.

Answer 2

Yes you add the exponents when multiplying the numbers and subtract when dividing. So

1) 3.87 x10^20 is correct
2) 5.5 x 10^11 is also correct

Answer 3

for the first, yes you add the exps up, 3.87 x 10^20

for the second , you got it right, you know what you're doing.

Answer 4

Right on!!