Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 02 Aug 2015, 16:52

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Math: Exponents Addition and Subtraction rules

Author Message
TAGS:
Intern
Joined: 17 Oct 2009
Posts: 14
Followers: 0

Kudos [?]: 0 [0], given: 1

Hello Guys,

What are the rules on adding and subtracting exponents?

For example: 2^5+2^5+2^5+3^5+3^5?

Is there a quick way to solve this?

(I know the multiplication, division and exponent rules on exponents.)

Cheers,
MathFear
CEO
Joined: 17 Nov 2007
Posts: 3574
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 424

Kudos [?]: 2296 [0], given: 359

Re: Math: Exponents Addition and Subtraction rules [#permalink]  26 Dec 2009, 14:41
Expert's post
It would go this way:

$$2^5+2^5+2^5+3^5+3^5 = (2^5+2^5+2^5)+(3^5+3^5) =$$

$$3*2^5+2*3^5 = 2*3* (2^4+3^4) =$$

$$6 * (16+81) = 6 * 97 = 6*(100-3) = 600 - 18 = 582$$
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Intern
Joined: 17 Oct 2009
Posts: 14
Followers: 0

Kudos [?]: 0 [0], given: 1

Re: Math: Exponents Addition and Subtraction rules [#permalink]  10 Jan 2010, 03:56
walker wrote:
It would go this way:

$$2^5+2^5+2^5+3^5+3^5 = (2^5+2^5+2^5)+(3^5+3^5) =$$

$$3*2^5+2*3^5 = 2*3* (2^4+3^4) =$$

$$6 * (16+81) = 6 * 97 = 6*(100-3) = 600 - 18 = 582$$

Hi walker, thank you for your response!

However, I noticed that I didn't copy the question right.

I meant:

2^5 + 2^5 + 3^5 + 3^5 + 3^5

And a Math guy showed me a fast way to calculate this. For me this is a typical trick I'd fall for. I'll just post the fast solution, for my fellow mathn00bs

2 * 2^5 = 2^6 (Because 2 = 2^1 and when multiplying exponents one needs to add them up.)
3 * 3^5 = 3^6 ( // )

So 2^5 + 2^5 + 3^5 + 3^5 + 3^5 = 2^6 + 3^6 (This was the answer they were looking for in the question)
Re: Math: Exponents Addition and Subtraction rules   [#permalink] 10 Jan 2010, 03:56
Similar topics Replies Last post
Similar
Topics:
3 Addition/Subtraction/Multiplication Tables 0 29 Oct 2014, 07:01
Please explain exponent rule 2 21 Jan 2012, 04:27
1 Exponent rule 2 06 Jul 2011, 07:24
2 Rules of Exponents 3 09 Jun 2011, 09:15
If x and y are positive integers, is x^16 - y^8 + 345y^2 div 5 28 Apr 2010, 23:29
Display posts from previous: Sort by