## help_people one year ago Which polynomial is a difference of two squares? x2 − 16 x2 + 16 x2 − 8 x2 + 8

1. help_people

@amistre64 @Mehek14

2. dinamix

its first one

3. Jhannybean

According to what we know about polynominals, let's say we take $$x=a$$ and $$4 =b$$ Then we can take our form, $$a^2-b^2$$ to write out our function as $$(x)^2-(4)^2$$ which simplifies to.....?

4. dinamix

$x^2-16 = (x-4)(x+4)$@help_people and $x^2-8 = (x-\sqrt{8})(x+\sqrt{8})$

5. help_people

ok @Jhannybean and @dinamix I know the answer but could you explain more for osme reason i do not get it

6. zzr0ck3r

@help_people You re looking for the form $$a^2-b^2$$ and the things is, when it is a variable, we can have it be $$x^2$$ so its the other part we are concerned with. So since we need a $$-$$ sign, we can rule out options 2 and 4. Ok so what is the problem with $$x^2-8$$ Well in order for it to be a perfect square, we need the thing after the $$-$$ sign to be written as $$b^2$$ where $$b$$ is a INTEGER. $$\sqrt{8}$$ is not an integer, but $$\sqrt{16}=4$$ is.

7. zzr0ck3r

so we have $$x^2-16=x^2-4^2$$

8. help_people

ok

9. dinamix

@help_people u study number complexe , @zzr0ck3r

10. dinamix

not you i am sopke with him , i ask if study it

11. zzr0ck3r

I am not sure what you are asking. I am good in certain area dealing with complex numbers, but not the traditional. There are much better people here for that.

12. Jhannybean

I really like your explanation here, @zzr0ck3r

13. zzr0ck3r

hi @Jhannybean

14. zzr0ck3r

ty :)

15. dinamix

@zzr0ck3r i hope know how to explain like u

16. zzr0ck3r

often my problem is over explaining. I have to learn to say only the things that are important. Some stuff I said up there is not 100% correct, but if I say it 100% correct often I would confuse everyone.

17. help_people

ok thank you for everthing :/ @zzr0ck3r XOXO to all