BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

If \(\dfrac1{x-2}=\dfrac1{x+2}+\dfrac1{x-1},\) which of the following is a possible value of \(x?\)

Expert replies
by Vincen » Sun May 23, 2021 12:18 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

If \(\dfrac1{x-2}=\dfrac1{x+2}+\dfrac1{x-1},\) which of the following is a possible value of \(x?\)

A. -2
B. -1
C. 0
D. 1
E. 2

Answer: C

Source: Manhattan GMAT
Join the discussion
Source: — Problem Solving |

Vincen wrote:
Sun May 23, 2021 12:18 pm
If \(\dfrac1{x-2}=\dfrac1{x+2}+\dfrac1{x-1},\) which of the following is a possible value of \(x?\)

A. -2
B. -1
C. 0
D. 1
E. 2

Answer: C

Source: Manhattan GMAT
A super-fast approach is to test the answer choices

IMPORTANT: Our work will be made even faster if we recognize that none of denominators (in the given equation) can equal zero. Otherwise, that fraction will be undefined.
So, we can automatically eliminate answer choices A, D and E, since they will all yield denominators that are equal to 0.

We're left with only answer choices B and C (and we haven't even done any work yet!!!)

Let's test answer choice B
Replace x with -1 to get: 1/[(-1) – 2] = 1/[(-1) + 2] + 1/[(-1) – 1]

Simplify to get: -1/3 = 1/1 + (-1/2)
Doesn't work!!
Eliminate house for choice B.

By the process of elimination, the correct answer is C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion