# Exponent problem

• Mar 24th 2010, 02:23 PM
artabro
Exponent problem
Which of the following is equal to (1/4) * (20^8)?

Options:
5^6
5^8
20^2
4*(20^7)
5(20^7)

Sincerely, I'm not able to get any of the results offered...

• Mar 24th 2010, 02:31 PM
tonio
Quote:

Originally Posted by artabro
Which of the following is equal to (1/4) * (20^8)?

Options:
5^6
5^8
20^2
4*(20^7)
5(20^7)

Sincerely, I'm not able to get any of the results offered...

$\frac{20^8}{4}=\frac{(4\cdot 5)^8}{4}=\frac{4^8\cdot 5^8}{4}=4^7\cdot 5^8=5(4^7\cdot 5^7)=$ ...
You can start by saying $20^8 = (20)^8 = (4\times 5)^8 = 4^8\times 5^8$