1.) 36x+18xy-9y-18

2.) 4-36x^2

3.) 42x^2-24

4.) 12x^2-5xy-3y^2

5.) -14r^2-11rs+15s^2

6.) x^4-x^2-30

I'm really struggling with this so any help would be greatly appreciated!

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- Sep 17th 2008, 03:20 PMepetrikFactoring! YUCK!
1.) 36x+18xy-9y-18

2.) 4-36x^2

3.) 42x^2-24

4.) 12x^2-5xy-3y^2

5.) -14r^2-11rs+15s^2

6.) x^4-x^2-30

I'm really struggling with this so any help would be greatly appreciated! - Sep 17th 2008, 03:29 PMJhevon
factor by grouping. there is a common 18x in the first two terms, and a common -9 in the last two

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2.) 4-36x^2

now apply the formula for the difference of two squares factorization

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3.) 42x^2-24

now, what do you aee?

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4.) 12x^2-5xy-3y^2

here's a tip: forget the y for a while and treat it as and factor that. when finished, attach a y to the constant terms, and that will take care of the y's in your expression

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5.) -14r^2-11rs+15s^2

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6.) x^4-x^2-30

this is a quadratic in , factor it as you would a quadratic. but instead of you are using

if it is hard for you to visualize, let , then you have . factorize this, and then replace all the 's with 's - Sep 17th 2008, 04:29 PMepetrikSTILL trying to factor!
- Sep 17th 2008, 04:35 PMJhevon
for 2, recall that

what is your and in #2?

as for the others, can you factorize the ones i gave? namely, (you can use the AC-method, please tell me you know what that is :D) and (remember how to deal with these guys? think of two numbers that you can multiply to get -30 (the constant term) and add to get -1 (the coefficient of y) then put them in the positions of the *'s as in (y + *)(y + *)) - Sep 17th 2008, 05:01 PMepetrik
THANK YOU THANK YOU THANK YOU!!!!!!!

I totally forgot about the AC Method! (Rofl)