DS Help Needed!!!!

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DS Help Needed!!!!

by Shadow » Tue Jul 10, 2007 2:58 am
If b,c, and d are constants and x^2+bx+c=(x+d)^2 for all values of x,what is the value of c?

(1) d=3
(2) b=6

What could be the answer?
Source: — Data Sufficiency |

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by discreet » Tue Jul 10, 2007 5:24 am
Is it D?Each statement is sufficient...

if you resolve the equation,you have

x^2 + bx +c = x^2 + d^2 + 2xd

Equating the co-efficients....you can conclude that

d^2=c,
2d=b

Using these equations it is possible to find the value of c if b or d is given 8)

So, D

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by highfive287 » Wed Jul 25, 2007 8:05 pm
discreet wrote:Is it D?Each statement is sufficient...

if you resolve the equation,you have

x^2 + bx +c = x^2 + d^2 + 2xd

Equating the co-efficients....you can conclude that

d^2=c,
2d=b

Using these equations it is possible to find the value of c if b or d is given 8)

So, D

How can you equate the co-efficients to get d^2 = c???

I think the answer should be C since you can only simplified the equation

as bx + c = 2 xd + d ^ 2 ( after canceling x^2) . You need to know the

value of b and d to determine c

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yep

by roopachet » Wed Aug 01, 2007 7:05 pm
even i think the answer is C

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by beny » Wed Aug 01, 2007 7:16 pm
Roopachet, PLEASE stop saying "even I". By saying this, you are implying that 1.) you are retarded and 2.) The question is extremely easy. Yet, the majority of the time you respond, you get the answer incorrect. Therefore, you confirm part 1 of your implication, but your improper implication of part 2 makes people who don't understand the question feel bad.

Anyway, the answer is D because the question states "for all values of X". Therefore, 2d = b ALWAYS and d^2 = c ALWAYS. Each statement alone is sufficient.

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by gabriel » Wed Aug 01, 2007 11:25 pm
beny wrote:Roopachet, PLEASE stop saying "even I". By saying this, you are implying that 1.) you are retarded and 2.) The question is extremely easy. Yet, the majority of the time you respond, you get the answer incorrect. Therefore, you confirm part 1 of your implication, but your improper implication of part 2 makes people who don't understand the question feel bad.

Anyway, the answer is D because the question states "for all values of X". Therefore, 2d = b ALWAYS and d^2 = c ALWAYS. Each statement alone is sufficient.
dude calm down .. No personal remarks on the forum ..

btw ... even I :wink: agree with D ..