# Math Help - Can someone help me with this pre-Calculus question?

1. ## Can someone help me with this pre-Calculus question?

If 2x2-dx+(31-d2)x+5 has a factor of x - d, what is the value of d if d is an integer?

2. ## Re: Can someone help me with this pre-Calculus question?

Let:

$f(x)=2x^2-dx+(31-d^2)x+5$

If $f(x)$ has a factor of $x-d$ then $f(d)=0$.

Hint: use the rational roots theorem on the resulting cubic in $d$.

3. ## Re: Can someone help me with this pre-Calculus question?

post problems in the precalculus forum please.

4. ## Re: Can someone help me with this pre-Calculus question?

so if f(d)=0 then then the new f(x) is 2x^2+31x+5??

5. ## Re: Can someone help me with this pre-Calculus question?

No, that doesn't mean to let d = 0, that means when x = d, f(x) = 0.