Question

Add or subtract exponents? I don't know when to add or subtract it's all confusing.
100^12/100^8

A.100^12/100^8
B.100^96
C.100^4
D.100^20
If I added it would be D
If I subtract it would be C
Please help I don't know which one is right. Thank you

Answer 1

when dividing numbers expressed as powers, you subtract the exponents. Think about it

10^7/10^3 =
10*10*10*10*10*10*10
---------------------------
10*10*10

Three of the factors cancel, and you are left with 7-3 = 4 multiples of 10. That is

10^(7-3) = 10^4

So, you want (C)