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

Redeem

Quadratics

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 158
Joined: Mon Nov 02, 2009 5:49 pm
Thanked: 2 times
Followed by:3 members

Quadratics

by tonebeeze » Tue Mar 08, 2011 7:53 am
What is the value of xy?

1. (x + y)^2 = 37
2. (x - y)^2 = 17

OA = C

Can someone walk me through the math please. Thanks.
Top
Source: — Data Sufficiency |
User avatar
Master | Next Rank: 500 Posts
Posts: 324
Joined: Mon Jul 05, 2010 6:44 am
Location: London
Thanked: 70 times
Followed by:3 members

by kmittal82 » Tue Mar 08, 2011 7:59 am
expand 1

x^2 + y^2 + 2xy = 37

expand 2

x^2 + y^2 - 2xy = 17

Subtract the two:

4xy = 20
xy = 5

Enough info to answer the question
Top
Post new topic Post Reply
• Page 1 of 1