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

Redeem

(x + a)(x + b)

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Sat Jun 06, 2009 9:33 pm
In a quadratic equation

x^2+3x+c = (X+a) (x+b)

The factors are a and b (this means -a and -b are the roots of this quadratic)

3 is nothing but sum of the factors (a+b)
c is nothing but product of the factors(a*b)

Stmt I

a=1
a+b = 3
1+b=3
b=2

we can find c= a*b (1*2)

SUFF

Stmt II

b=2

We know a+b=3 and b=2 so a=1

c=a*b = 1*2 = 2

SUFF

Hope I dint miss something. I have explained in detail but once we get the concept we dont have to even waste time doing the above.

Let me know if u still hv questions.

D
Top
Legendary Member
Posts: 882
Joined: Fri Feb 20, 2009 2:57 pm
Thanked: 15 times
Followed by:1 members
GMAT Score:690

by crackgmat007 » Mon Jun 08, 2009 8:23 am
great explanation...i get it. tx much
Top
Post new topic Post Reply
• Page 1 of 1