Help with an exponent question

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 26
Joined: Mon Apr 27, 2009 6:37 am
Location: South NJ, right outside of Philly
Thanked: 1 times
GMAT Score:420

Help with an exponent question

by anthony.j » Sun May 03, 2009 10:54 am
Hi,

My mind is spinning right now and I can't seem to figure out how to get to this answer. Please help! Thanks!

Which of the following is equal to the value of:
2^5 + 2^5 + 3^5 + 3^5 + 3^5

answer: 2^6 +3^6

Master | Next Rank: 500 Posts
Posts: 125
Joined: Sun Sep 16, 2007 1:38 pm
Thanked: 6 times

by chetanojha » Sun May 03, 2009 11:05 am
Take 2^5 and 3^5 common
2^5(1+1)+3^5(1+1+1) = 2*2^5+3*3^5 =2^6+3^6

Junior | Next Rank: 30 Posts
Posts: 26
Joined: Mon Apr 27, 2009 6:37 am
Location: South NJ, right outside of Philly
Thanked: 1 times
GMAT Score:420

by anthony.j » Sun May 03, 2009 11:19 am
chetanojha wrote:Take 2^5 and 3^5 common
2^5(1+1)+3^5(1+1+1) = 2*2^5+3*3^5 =2^6+3^6
Oh, I see what you did now. After taking the common factor you are left with the two equations. Then it is simply multiplication.

So simple, yet so hard to figure it out when stuck.

Thanks!!

Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Wed Jan 14, 2009 1:19 pm

by cneal4 » Mon May 04, 2009 7:56 am
Thanks that helped me also in understanding that a little better.

User avatar
Junior | Next Rank: 30 Posts
Posts: 20
Joined: Mon Jul 07, 2008 7:05 am
Location: Back of Beyond

Re: Help with an exponent question

by ousek » Sun Jun 28, 2009 8:09 am
anthony.j wrote: 2^5 + 2^5 + 3^5 + 3^5 + 3^5
= 2*(2^5) + 3*(3^5)
= 2^6 + 3^6

Hope this will help...
Fucking GMAT

Senior | Next Rank: 100 Posts
Posts: 85
Joined: Wed Aug 13, 2008 2:21 am
Thanked: 1 times

Re: Help with an exponent question

by sudi760mba » Thu Jul 02, 2009 12:04 am
When you have to add exponents, always factor

2^5(1 + 1) = 2^5(2) which is the same as 2^5(2^1).

With the rule
x^x * x^y = x^x + y

2^5(2^1) = 2^5+1 = 2^6

3^5(1 + 1 + 1) = 3^5(3) which is the same as 3^5(3^1)

With the rule
x^x * x^y = x^x + y

3^5(3^1) = 3^5 + 1 = 3^6


anthony.j wrote:Hi,

My mind is spinning right now and I can't seem to figure out how to get to this answer. Please help! Thanks!

Which of the following is equal to the value of:
2^5 + 2^5 + 3^5 + 3^5 + 3^5

answer: 2^6 +3^6