## anonymous one year ago how do i factor a^2-b^2-4b-4?

1. steve816

I don't think it's factorable...

2. steve816

\[a^2-b^2-4b-4\]

3. anonymous

Oh...I got stuck at (a+b)(a-b)-4(b+1). Thanks! For some reason, if you insert the equation into http://www.wolframalpha.com/widgets/view.jsp?id=e7040eab64a24724666a4991fb077bd2, it can be factorable

4. anonymous

^^wolfram factoring calculator http://www.wolframalpha.com/widgets/view.jsp?id=e7040eab64a24724666a4991fb077bd2

5. Directrix

a^2 - b^2 -4b - 4 = a^2 - ( b^2 +4b + 4)

6. Directrix

This expression is the difference of the perfect square a^2 and the perfect square trinomial ( b^2 +4b + 4)

7. anonymous

Yes, that was what the answer was suppose to be. I always end up grouping the wrong polynomials. Thanks.

8. Directrix

a^2 - ( b^2 + 4b + 4) = a^2 - [(b + 2)*(b+2)] = a^2 - ( b + 2)^2 =

9. Directrix

a^2 - ( b + 2)^2 = ? @one234 (I grouped the wrong ones together on my first try, too. :) )

10. anonymous

(a+b+2)(a-b+2)

11. Directrix

a^2 - ( b + 2)^2 = [ a + (b + 2 ) ] * [ a - ( b + 2 ) ]

12. Directrix

I think you have a sign error in distributing the negative here: [ a - ( b + 2 ) ]

13. Directrix

- ( b + 2 ) The negative applies to both the b and the 2. So, what would be the correct answer? @one2345 (Or, did I mess up?)

14. anonymous

(a-b-2) I didn't realize it was necessary to use the parentheses. :P

15. Directrix

[ a + (b + 2 ) ] * [ a - ( b + 2 ) ] = (a + b + 2) * (a - b - 2)

16. anonymous

Thank you again.

17. anonymous

would you mind showing me how to do one more factoring problem?

18. Directrix

Glad to help. Try the problem I attached. Post what you get, okay?

19. anonymous

|dw:1443592919361:dw|

20. anonymous

Could you check my work for this problem? I did something wrong...

21. anonymous

|dw:1443593102956:dw|

22. anonymous

|dw:1443593233945:dw|

23. Directrix

This looks okay - now simplify within parentheses.

24. anonymous

|dw:1443593838420:dw|

25. anonymous

|dw:1443593990406:dw|

26. Directrix

|dw:1443594027672:dw|

27. Directrix

@one2345 Good work!

28. anonymous

I was doing this on paper and I just realized my error and corrected it online. Anyway, thank you so much for helping me. I really appreciate it.

29. Directrix

You are welcome. If you want to practice tomorrow, I'll look for you.

30. anonymous

That's fine. :) I'm studying today for a factoring quiz i have tomorrow. I have to leave now, good night!