If a·b≠0, and (x+a)(x+b)=0, is x=a?
(1) x−b=0
(2) a=−b
OA - A
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
is x = a?
This topic has expert replies
-
eshwarjayanth
- Senior | Next Rank: 100 Posts
- Posts: 40
- Joined: Mon Oct 18, 2010 8:32 am
-
GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Given (x+a)(x+b)=0, either x+a = 0 or x+b = 0.eshwarjayanth wrote:If a·b≠0, and (x+a)(x+b)=0, is x=a?
(1) x−b=0
(2) a=−b
OA - A
Statement 1: x-b = 0.
Thus, x+b ≠0, implying that x+a = 0 and that x = -a.
Thus, we know that x≠a.
SUFFICIENT.
Statement 2: a=−b.
Subtituting b=-a into (x+a)(x+b)=0, we get:
(x+a)(x-a) = 0.
If x+a = 0, then x = -a.
If x-a = 0, then x=a.
INSUFFICIENT.
The correct answer is A.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
