Factor completely x2 + 20x − 36.

(x − 2)(x − 18)
(x + 2)(x − 18)
(x − 2)(x + 18)
Prime

I think its prime.. correct ?

Question

Factor completely x2 + 20x − 36.

 (x − 2)(x − 18)
 (x + 2)(x − 18)
 (x − 2)(x + 18)
 Prime 

I think its prime.. correct ?

skullpatrol · Answer

Multiply out the other answer choices and find out :-)

skullpatrol · Answer

Do you know FOIL?

gabylovesyou · Answer

i don't think it can be factored... so if u can't, its prime right ?

gabylovesyou · Answer

nd yes i do

skullpatrol · Answer

Yes, just like an integer:

If it can not be factored, then it is prime.

gabylovesyou · Answer

Thank you

skullpatrol · Answer

Thanks  for asking :-)

zarkon · Answer

it does factor

$$x^2 + 20x - 36=(x+2(5-\sqrt{34}))(x+2(5+\sqrt{34}))$$

it just doesn't factor over the integers

gabylovesyou · Answer

ohhh okkk tyty :D

skullpatrol · Answer

A polynomial cannot  be factored over the set of polynomials with the integer coefficients is called a prime polynomial.

skullpatrol · Answer

An integer that cannot  be factored over the set of integers is called a prime number.