Lesson: Simplifying Roots

Comment on Simplifying Roots

i am facing an issue regarding sound in different videos.i need help regarding the same issue.
gmat-admin's picture

I just checked several issues, and the volume is fine for all of them. I suggest that you clear the cache of your Web browser, then restart your computer and see if that resolves the issue?

Here are the instructions for clearing your cache: https://kb.iu.edu/d/ahic

Note: you need not clear your cookies or your browsing history.

Good day

one issue I have is determining the primes to use for large numbers such as the 756, because I mean it could take forever to try and test different prime number to get to such a large number.

Any time saving recommendations?

Thanks
gmat-admin's picture

Hi Schalla14,

You'll see that, to factor 756, you need only know the divisibility rules for 2 and 3. So, it shouldn't take long to find the prime factorization.

On test-day, you won't be required to simplify the square root of a large number that has, within it, big prime factors. For example, you wouldn't need to deal with something like √2023.

ASIDE: 2023 = (17)(17)(7)
So, √2023 = √(17²)(7)
= (√17²)(√7)
= 17√7

Hey Brent,

is there a specific strategy/rules how to pick the numbers? Or is it just trial and error?

Cheers.
gmat-admin's picture

It's a good idea to start with small values such as 2, 3 and 5.
This will quickly break the number into smaller and smaller pieces.

in 4:56, can you please post the links for the exact videos you are referring to? the integers property module is pretty dense. thanks.
gmat-admin's picture

Good question.
Here's the video: https://www.gmatprepnow.com/module/gmat-integer-properties/video/825

Cheers,
Brent

Add a comment

Office Hours

Have questions about your preparation or an upcoming test? Need help modifying the Study Plan to meet your unique needs? No problem. Just book a Skype meeting with Brent to discuss these and any other questions you may have. 

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.

Have a question about this video?

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

Free “Question of the Day” emails!