Question: Product with Roots

You need an account to watch this video

flag video to
rewatch later

Comment on Product with Roots

One can be faster if one uses

Kevin - December 17, 2016

One can be faster if one uses a^2 - b^2 = (a+b)(a-b)

Agreed!

greenlight-admin - December 17, 2016

Agreed!
The reason I don't use it here is that we haven't yet covered Differences of Squares in the module.

My goal for this practice question is to make people recognize that products of the form (a + b)(a - b) have a unique outcome. Then, when we cover differences of squares (two videos from now), they will recognize the form from this practice question.

so you can use foil without

lethalasian - October 28, 2019

so you can use foil without variables? as long as it is in
(# + #)(# + #)form

That's correct.

greenlight-admin - October 28, 2019

That's correct.
Keep in mind that the variables are representing numbers. So, what applies to variables also applies to numbers.

Cheers,
Brent

Have a question about this video?

Post your question in the Comment section below, and a GRE expert will answer it as fast as humanly possible.

Change Playback Speed

You have the option of watching the videos at various speeds (25% faster, 50% faster, etc). To change the playback speed, click the settings icon on the right side of the video status bar.

Let me Know

Have a suggestion to make the course even better? Email us today!