Source: Official Guide for GMAT Review 2016 Problem Solving; #206
Yannaphol Kaewbaidhoon
key step here is the difference fo squares (a^2 - b^2) = (a-b)(a+b)
Sep 4, 2017 • Comment
Sam Kinsman
Yes, that's right! :)
Sep 12, 2017 • Reply
Mike McGarry, Magoosh Tutor
Aug 17, 2015 • Comment
Mumin Khan
This problem is just sadistic.
Oct 12, 2017 • Reply
Jonathan , Magoosh Tutor
It's not easy! :) But it's important to know your FOIL identities COLD, including (a^2 - b^2) = (a + b)(a - b)
Nov 6, 2017 • Reply
Roger Kille
True
Jul 30, 2018 • Reply
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