Polynomials

Expert replies

tonebeeze: Master | Next Rank: 500 Posts; Posts: 158; Joined: Mon Nov 02, 2009 5:49 pmFollowed by: 3 members; Thanked: 2 times

by tonebeeze » Tue Apr 26, 2011 3:02 pm

I got this problem correct, however I am interested in reviewing the different approaches to solving this problem. Thanks!

What is the value of (x-y)^4?

1. The product of x and y is 7

2. x and y are integers

OA = C

Like this post

Source: Beat The GMAT — Data Sufficiency | Tue Apr 26, 2011 3:02 pm

Tani: Legendary Member; Posts: 1255; Joined: Fri Nov 07, 2008 2:08 pmFollowed by: 90 members; Location: St. Louis; Thanked: 312 times

by Tani » Tue Apr 26, 2011 4:02 pm

Since you can have positive and negatives or fractions, the first statement gives you an infinite number of pairs of values for X and Y, as long as their product is seven.
The second is also useless on its own.

However if the product of x and y is seven and they have to be integers then we are looking at 1 and 7 or -1 and -7. Their sum will either be -6 or +6 = either will give you the same value for 6^4.

Tani Wolff

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review