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

Redeem

What is -a + b - c + d

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

What is -a + b - c + d

by sanju09 » Sat Jun 19, 2010 2:22 am
What is -a + b - c + d if (x - 1/5) (x + 1) (x + 3/7) = a x^3 + b x^2 + c x + d for all real values of x?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Sat Jun 19, 2010 2:26 am
sanju09 wrote:What is -a + b - c + d if (x - 1/5) (x + 1) (x + 3/7) = a x^3 + b x^2 + c x + d for all real values of x?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4
put x = -1. then

-a + b - c + d = (-1 - 1/5) (-1 + 1) (-1 + 3/7)
=0

A
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Sat Jun 19, 2010 2:29 am
kvcpk wrote:
sanju09 wrote:What is -a + b - c + d if (x - 1/5) (x + 1) (x + 3/7) = a x^3 + b x^2 + c x + d for all real values of x?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4
put x = -1. then

-a + b - c + d = (-1 - 1/5) (-1 + 1) (-1 + 3/7)
=0

A
stunning approach
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Post new topic Post Reply
• Page 1 of 1