If x is an integer, then how many values of x will satisfy the equation

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
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
BTGModeratorVI wrote:
Thu Aug 27, 2020 12:09 pm
If x is an integer, then how many values of x will satisfy the equation ||x - 2| + 7| = 6?

A) 0
B) 1
C) 2
D) 3
E) 4

Answer: A
Source: e-GMAT
Given: ||x - 2| + 7| = 6
This means EITHER |x - 2| + 7 = 6 OR |x - 2| + 7 = -6
Let's examine each possibility....

Take: |x - 2| + 7 = 6
Subtract 7 from both sides to get: |x - 2| = -1
Since the absolute value of any expression will ALWAYS be greater than or equal to 0, we can see that the equation |x - 2| = -1 has no solution.

Take: |x - 2| + 7 = -6
Subtract 7 from both sides to get: |x - 2| = -13
Since the absolute value of any expression will ALWAYS be greater than or equal to 0, we can see that the equation |x - 2| = -13 has no solution.

Since there are no values of X that will satisfy the original equation, correct answer is A

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members
BTGModeratorVI wrote:
Thu Aug 27, 2020 12:09 pm
If x is an integer, then how many values of x will satisfy the equation ||x - 2| + 7| = 6?

A) 0
B) 1
C) 2
D) 3
E) 4

Answer: A
Solution:

We could have |x - 2| + 7 = 6 or |x - 2| + 7 = -6 (since |6| = |-6| = 6).

If |x - 2| + 7 = 6, then |x - 2| = -1. However, an absolute value can’t be negative, so there are no solutions to this equation.

If |x - 2| + 7 = -6, then |x - 2| = -13. Again, an absolute value can’t be negative, so there are no solutions to this equation either.

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage