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

Redeem

Square Root of Variables

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 113
Joined: Sun Nov 24, 2013 9:19 pm
Thanked: 1 times
Followed by:5 members

Square Root of Variables

by bml1105 » Sat Dec 21, 2013 6:24 pm
MGMAT - Algebra Guide Chapter 4: Roots, Problem Set #11

Solve of simplify the following problem:

√x^2y^3 = 3x^2y^3

Answer = [spoiler]2xy√y[/spoiler]

Why not [spoiler]2x√2y^3[/spoiler]?
Top
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Sat Dec 21, 2013 6:33 pm
bml1105 wrote:MGMAT - Algebra Guide Chapter 4: Roots, Problem Set #11

Solve of simplify the following problem:

√x^2y^3 = 3x^2y^3

Answer = [spoiler]2xy√y[/spoiler]

Why not [spoiler]2x√2y^3[/spoiler]?
Hi!

First, the problem you posted doesn't actually include a question, so I'm not sure for what you're solving. In other words, you posted an equation, but no question.

However, I can still answer your question - the official answer you posted and your answer are actually identical.

We can rewrite 2x√2y^3 as 2x√2(y*y^2)

and then we can take "y^2" our of the root to get the accredited answer.

Looking at a simpler example:

√y^3 = √y^2*y = √y^2 * √y = y√y
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 113
Joined: Sun Nov 24, 2013 9:19 pm
Thanked: 1 times
Followed by:5 members

by bml1105 » Sat Dec 21, 2013 9:24 pm
Sorry, the question was just to solve or simplify. However, my equation wasn't clear and I accidentally put an equals sign where there should be a plus sign.

The equation I'm supposed to simplify is: √[(x^2)(y^3) + (3x^2)(y^3)]
Top
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Sun Dec 22, 2013 1:22 am
bml1105 wrote:Sorry, the question was just to solve or simplify. However, my equation wasn't clear and I accidentally put an equals sign where there should be a plus sign.

The equation I'm supposed to simplify is: √[(x^2)(y^3) + (3x^2)(y^3)]
No worries! It didn't really affect your question or my response, I was just curious.

Stuart
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 113
Joined: Sun Nov 24, 2013 9:19 pm
Thanked: 1 times
Followed by:5 members

by bml1105 » Sun Dec 22, 2013 5:25 pm
Thanks! I see it now.
Top
Post new topic Post Reply
• Page 1 of 1