Exponent Question

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Thu Oct 02, 2008 9:53 pm

Exponent Question

by shaden » Wed Oct 29, 2008 7:29 am
This is probably simple, but my weak point is exponents and roots.

If the question is (2^2)/(2^-2) = ?

Since it is division with similiar bases, you subtract exponents correct? Therefore, is it:
2^(2-2) =2^0 = 1

or
2^(2--2) = 2^(2+2) =2^4 = 16?

Thanks

Newbie | Next Rank: 10 Posts
Posts: 5
Joined: Sat Feb 23, 2008 1:36 pm
GMAT Score:650

Re: Exponent Question

by herjari » Wed Oct 29, 2008 7:52 am
shaden wrote: 2^(2--2) = 2^(2+2) =2^4 = 16?
Second option is the correct one.

What you have to remember is that 1/2^-2 = 2^2

Best wishes,

H

User avatar
Legendary Member
Posts: 519
Joined: Sat Jan 27, 2007 7:56 am
Location: India
Thanked: 31 times

Re: Exponent Question

by Neo2000 » Wed Oct 29, 2008 7:56 am
shaden wrote:This is probably simple, but my weak point is exponents and roots.

If the question is (2^2)/(2^-2) = ?

Since it is division with similiar bases, you subtract exponents correct?
or
2^(2--2) = 2^(2+2) =2^4 = 16?

Thanks
You certainly subtract the exponents. However the sign of the exponent is important. You cannot change the sign as you did for the first answer. That is incorrect. The 2nd approach is the right way.