If 2^b = 48^5/12^5, what is the value of b?
The way I did this was:
48^5 = (4*12)^5
so (4*12)^5/12^5 the 12^5's cross out
So you are left with (2^2)^5
which I thought was 2^7 so b is 7 but the answer is 10, can anyone explain please?
Thanks again!
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Exponents
This topic has expert replies
-
[email protected]
- Senior | Next Rank: 100 Posts
- Posts: 62
- Joined: Thu Jul 03, 2008 4:52 am
-
sudhir3127
- Legendary Member
- Posts: 829
- Joined: Mon Jul 07, 2008 10:09 pm
- Location: INDIA
- Thanked: 84 times
- Followed by:3 members
hey karen
u did everything correct ..only missed the last point
4^5 ca be writtenas (2^2)^5 which 2^10
( a^m)^n = a^m*n= a^mn
hope its clear now..
u did everything correct ..only missed the last point
4^5 ca be writtenas (2^2)^5 which 2^10
( a^m)^n = a^m*n= a^mn
hope its clear now..
-
VP_RedSoxFan
- GMAT Instructor
- Posts: 85
- Joined: Thu May 01, 2008 12:56 pm
- Location: Salt Lake City, UT
- Thanked: 24 times
- GMAT Score:750+
this is a good time to refresh even myself on the exponent rules:
(a^m)^2 = a^(2m)
(ab)^2 = a^2 * b^2
(a+b)^2 = a^2 + 2ab + b^2
etc.
You did such a good job up until applying this rule, I hate to see hard earned points escape us...
(a^m)^2 = a^(2m)
(ab)^2 = a^2 * b^2
(a+b)^2 = a^2 + 2ab + b^2
etc.
You did such a good job up until applying this rule, I hate to see hard earned points escape us...
Ryan S.
| GMAT Instructor |
Elite GMAT Preparation and Admissions Consulting
www.VeritasPrep.com
Learn more about me
| GMAT Instructor |
Elite GMAT Preparation and Admissions Consulting
www.VeritasPrep.com
Learn more about me
-
[email protected]
- Senior | Next Rank: 100 Posts
- Posts: 62
- Joined: Thu Jul 03, 2008 4:52 am
