Which of the following polynomials has -3 as a zero?

1
(x - 3)
2
x2 - 9
3
x2 - 3x
4
x2 + 3

Question

Which of the following polynomials has -3 as a zero?

1		
             (x - 3)
2		
                   x2 - 9
3		
                        x2 - 3x
4		
                                    x2 + 3

parthkohli · Answer

If $x + 3$ is a factor, then $-3$ is a zero.

parthkohli · Answer

Factor all the polynomials you are given, and if any of those has $x + 3$ as a factor, then VOILA! $-3$ is a zero.

anonymous · Answer

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parthkohli · Answer

Yeah, that's what I am talking about. :-)

anonymous · Answer

@ParthKohli You're bcoming 1/2 helpful

anonymous · Answer

I gave you options @ParthKohli

parthkohli · Answer

Can you factor all of those choices?

anonymous · Answer

factorising second option will give you (x+3) (x-3). So, probably there you have -3 as zero

parthkohli · Answer

If you don't want to d it the hard way, just plug in $-3$ in all the choices and see where you get $0$.

anonymous · Answer

x^2 - 9
9-9
0