Lesson: Basic Equation Solving

Rate this video: 

Comment on Basic Equation Solving

Hi Brent,
In your solution to this question

Given: (x − y)² = x² + y²
(x − y) (x − y) = x² -xy -xy +y² --> x² -2xy +y² = x² + y²
How you got it x² - xy + y² = x² + y²
where is the 2 in -2xy, although it will disappear in the next steps when we divide by -2, but I am just curious why it disappeared before, or maybe I am missing something..
Thank you.
gmat-admin's picture

Good catch - thanks!!
I have edited my solution here: https://gmatclub.com/forum/if-x-y-2-x-2-y-2-then-which-one-of-the-follow...


Add a comment

Ask on Beat The GMAT

If you have any questions, ask them on the Beat The GMAT discussion forums. The average response time is typically less than 30 minutes.

Change Playback Speed

To watch our videos at faster speeds (e.g., 20% or 50% faster), download this free extension for your Chrome web browser.  

Have a question about this video?

Post your question in the Comment section below, and we’ll answer it as fast as humanly possible.