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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

number properties / functions

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Legendary Member
Posts: 833
Joined: Mon Aug 04, 2008 1:56 am
Thanked: 13 times

by vivek.kapoor83 » Sat Oct 11, 2008 9:30 am
IMO E.
coz f(a+b) = f(a)+f(b)
we have to prove.,
then
putiing x=a+b in E
f(a+b) = -3(a+b) = -3a-3b
put x = a
f(a) = -3a
put x =b
f(b) = -3b
f(a)+f(b) = -3a-3b

Hence,E.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pmFollowed by: 11 members
Thanked: 331 times

by cramya » Sat Oct 11, 2008 9:44 am
It should be E

This ha sbeen solved in this forum before but cant find the link

Pick numbers lets say a=2 b=3

f(5) = f(2) + f(3)

x=5, x=2,x=3 WEvaluate the choices and E will be true
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 109
Joined: Mon Sep 08, 2008 12:47 am

by smallsorrow » Sat Oct 11, 2008 10:44 am
e is correct. thanks for explaining!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 9
Joined: Tue Sep 16, 2008 3:22 pm

by elmiko » Sat Oct 11, 2008 3:45 pm
cramya wrote:It should be E

This ha sbeen solved in this forum before but cant find the link

Pick numbers lets say a=2 b=3

f(5) = f(2) + f(3)

x=5, x=2,x=3 WEvaluate the choices and E will be true
I don't understand how you plug in the choices into each of the functions in the answer choices. Can you explain further?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 154
Joined: Tue Aug 26, 2008 12:59 pm
Location: Canada
Thanked: 4 times

by canuckclint » Sat Oct 11, 2008 5:58 pm
elmiko wrote:
cramya wrote:It should be E

This ha sbeen solved in this forum before but cant find the link

Pick numbers lets say a=2 b=3

f(5) = f(2) + f(3)

x=5, x=2,x=3 WEvaluate the choices and E will be true
I don't understand how you plug in the choices into each of the functions in the answer choices. Can you explain further?
You can plug for example
f(x) = x^2 take a = 2 b = 3
f(a+b) = f(5) = 5^2
not equal to
f(a) + f(b) = f(2) + f(3) = 2^2 + 3^2

Actually there is no need to plug if you got the right answer.
Just remember factoring from algebra.

k(a+b) = ka + kb for any k. just from algebra
Part E is just sucah a case with k=-3

Cheers,
Clinton
Math Minor
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1