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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Evaluating radical expressions - Please Help ASAP

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Wed Nov 11, 2009 9:06 am
by postroske » Tue Nov 24, 2009 8:16 pm
I am taking the GMAT tomorrow and felt prepared until I saw this question on the GMAT's software practice test. I can not figure out how to properly evaluate this expression.

(sqrt(9+sqrt(80)) + sqrt(9-sqrt(80)))^2

the ^2 indicates that the entire expression is to the second power or squared. I can not figure it out and would like to know before i go in tomorrow. If you can, please explain method.

Thanks!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 172
Joined: Wed Jul 09, 2008 3:35 amFollowed by: 1 member
Thanked: 3 times
GMAT Score:610

by karthikgmat » Tue Nov 24, 2009 10:59 pm
9 can be written as sqrt(5)^2+sqrt(4)^2 and sqrt(80) can be written as sqrt( 4*4*5)
it is square of (a+b)

so the first term is sqrt(5)+2
second term is sqrt(5) -2
adding two we get 2 sqrt(5)

finally squaring that 4*5 =20

..is it ok?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Thu Aug 27, 2009 6:05 am
Thanked: 5 times
GMAT Score:640

by nikilnikil » Wed Nov 25, 2009 12:47 am
this expression is of the form

(a+b)^2 = a^2+b^2+2*a*b

sqrt(9+sqrt(80)) ^2 + sqrt(9-sqrt(80))^2 + 2* sqrt((9+sqrt(80))*(9-sqrt(80))

= 9+sqrt(80) + 9 - sqrt(80) + 2 * (81-80) [because (a+b)(a-b) = a^2 -b^2]
=9+9+2 = 20

~Nik
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Wed Nov 11, 2009 9:06 am

by postroske » Wed Nov 25, 2009 6:27 am
thank you both. great explanation!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1