If for all x, x^2+ax+b=(x+c)^2, then a=? 1). b=0 2). c=-3

Question

If for all x, x^2+ax+b=(x+c)^2, then a=?
1). b=0
2). c=-3

Please provide explanations. thanks a lot.

ccax · Answer

x^2 + ax + b = (x + c)^2 = x^2 + 2cx + c^2

Now just compare the coefficients.

a= 2c, so (2) is sufficient and therefore B.

sm176811 · Answer

This is an easy problem. U will have to compare the coefficients of LHS with those of RHS

chiragr · Answer

1) b=0 => x^2+ax = (x+c)^2, 
now this equation can be satisfied 
if x=0 and c=0 
or a=0 and c=0, 

But question says for all x so only option is a=0, c=0 

Sufficient

2) c=-3 straight forward...sufficient

so answer is D

uanant · Answer

Answer is D
x^2 + ax + b = (x + c)^2
if you put b = 0 and solve for a
x^2 + ax = (x + c)^2
a = -x
At this point if you have the value of C you can find out a 
you need both statements to find out a for all values of x

If for all x, x^2+ax+b=(x+c)^2, then a=? 1). b=0 2). c=-3

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