Hello BTG
Would appreciate some help on the following question.
Thanks
Practice Exam 1 - GMAT Prep - Algebra
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2^(x+y)²/ 2^(x-y)² = 2^(x² + 2xy + y²)/ 2^(x² - 2xy + y²)if xy=1 then what is the value of 2^(x+y)²/ 2^(x-y)²
1)2
2) 4
3) 8
4) 16
5) 32
= 2^(4xy) [after we subtract exponents]
= 2^4 [since xy = 1]
= 16
= D
RELATED RESOURCE (video)
- Laws of exponents - part I: https://www.gmatprepnow.com/module/gmat ... video/1025
Cheers,
Brent
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
Alternate Approach.if xy=1 then what is the value of 2^(x+y)²/ 2^(x-y)²
1)2
2) 4
3) 8
4) 16
5) 32
Since we're told that xy = 1, let's lets x = 1 and y = 1
We get:
2^(x+y)²/ 2^(x-y)² = 2^(1+1)²/ 2^(1-1)²
= 2^(2)²/2^(0)²
= 2�/2�
= 16/1
= 16
= D
Cheers,
Brent