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
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
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.

715+ 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.

Which expression is equivalent to (5x − 3y)^2?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 2276
Joined: Sat Oct 14, 2017 6:10 amFollowed by: 3 members
by VJesus12 » Fri Apr 06, 2018 2:26 am
Which expression is equivalent to (5x − 3y)^2?

A. 10x − 6y
B. 25x − 9y
C. 25x^2 − 9y^2
D. 25x^2 − 15xy + 9y^2
E. 25x^2 − 30xy + 9y^2

The OA is E .

Seems like I make the calculations wrong. I got D. Can anyone help me? Thanks.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

GMAT Instructor
Posts: 41
Joined: Mon Mar 12, 2018 9:54 amFollowed by: 1 member

TTT

by Sionainn@PrincetonReview » Fri Apr 06, 2018 4:44 am
Yes it looks like you may have not multiplied one of the set of terms.

$$^{(5x-3y)^2}$$
= (5x - 3y)(5x - 3y)

We need to make sure we multiply all of the terms in the first set of parentheses by all of the terms in the second set. A common mnemonic folks use to make sure they multiply all the terms once is FOIL (first, outer, inner and last).

Multiply the FIRST term in each binomial: (5x)(5x) = $$^{25x^2}$$
Multiply the OUTER term (be careful with signs): (5x)(-3y) = -15xy
Multiply the INNER term (be careful with signs): (-3y)(5x) = -15xy
Then, multiply the LAST term in each binomial: (-3y)(-3y) = $$^{9y^2}$$

Finally combine the terms: $$^{25x^2}$$ + (-15xy) + (-15xy) + $$^{9y^2}$$ = $$^{25x^2}$$ - 30xy + $$^{9y^2}$$

Make sense?

Take care,

Sionainn Marcoux,
BA - Stanford University, MPP - Harvard University
Instructor, tutor for Princeton Review and Airbnb host
In other words a blend of Jamie Escalante from Stand and Deliver, Julie from The Love Boat, and Schneider the Super from One Day at a Time.

Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Sat Apr 07, 2018 5:02 am
VJesus12 wrote:Which expression is equivalent to (5x − 3y)^2?

A. 10x − 6y
B. 25x − 9y
C. 25x^2 − 9y^2
D. 25x^2 − 15xy + 9y^2
E. 25x^2 − 30xy + 9y^2
One option is to use the FOIL method to expand the product (that's the solution I'd typically use)
However, we can also use this approach:

First recognize that we're looking for an expression that's EQUIVALENT to (5x − 3y)^2 for all values of x and y
So, for example, let's determine the value of (5x − 3y)^2 when x = 0 and y = 1
Take (5x − 3y)^2 and replace x with 0 and y with 1 to get: [5(0) − 3(1)]^2 = [−3]^2 = 9

So, the answer choice that's EQUIVALENT to (5x − 3y)^2 must also evaluate to be 9 when x = 0 and y = 1
Let's check each answer choice...

A. 10(0) − 6(1) = -6. ELIMINATE
B. 25(0) − 9(1) = -9. ELIMINATE
C. 25(0^2) − 9(1^2) = -9. ELIMINATE
D. 25(0^2) − 15(0)(1) + 9(1^2) = 9. KEEP
E. 25(0^2) − 30(0)(1) + 9(1^2) = 9. KEEP

Okay, we have two possible answer choices remaining.
We need to plug in ANOTHER set of values.
How about x = 1 and y = 1
Take (5x − 3y)^2 and replace x with 1 and y with 1 to get: [5(1) − 3(1)]^2 = [2]^2 = 4
Let's check the two remaining answer choices...
D. 25(1^2) − 15(1)(1) + 9(1^2) = 19. ELIMINATE
E. 25(1^2) − 30(1)(1) + 9(1^2) = 4. KEEP

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8188
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Wed Apr 11, 2018 3:37 pm
VJesus12 wrote:Which expression is equivalent to (5x − 3y)^2?

A. 10x − 6y
B. 25x − 9y
C. 25x^2 − 9y^2
D. 25x^2 − 15xy + 9y^2
E. 25x^2 − 30xy + 9y^2
Let's expand the given expression:

(5x - 3y)^2 = (5x - 3y)(5x - 3y) = 25x^2 - 30xy + 9y^2

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1