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randyse · 2009 June 30th, 02:58 AM

Hello. I'm working the EZ Solutions Test Prep series of books and came across the following Algebra problem. I'll post what they say the answer is with how they arrived at it and the answer I arrived at and how I arrived at it.

Could someone please explain where I went wrong? Even with their explanation I don't get it.

10x² + 28xy + 18y²
Them:
(5x)(2x) + (+10 + 18)xy + (+9y)(+2y)
5x(2x + 2y) + 9y(2x + 2y)
(5x + 9y)(2x + 2y)

My solution: first I thought I should factor out 2:
2(5x² + 14xy + 9y²)
2[(5x + 9y)(x+y)]

Where did I go wrong?

Thanks,
Randy

abhishek_mumbai · 2009 June 30th, 07:33 AM

I don't see where you are wrong.. you take 2 inside the (x+y) and your answer will be same as OE..

2009 June 30th, 02:58 AM	#1 (permalink)
randyse I JUST got here. Join Date: Jun 2009 Posts: 2	Algebra question Hello. I'm working the EZ Solutions Test Prep series of books and came across the following Algebra problem. I'll post what they say the answer is with how they arrived at it and the answer I arrived at and how I arrived at it. Could someone please explain where I went wrong? Even with their explanation I don't get it. 10x² + 28xy + 18y² Them: (5x)(2x) + (+10 + 18)xy + (+9y)(+2y) 5x(2x + 2y) + 9y(2x + 2y) (5x + 9y)(2x + 2y) My solution: first I thought I should factor out 2: 2(5x² + 14xy + 9y²) 2[(5x + 9y)(x+y)] Where did I go wrong? Thanks, Randy

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2009 June 30th, 07:33 AM	#2 (permalink)
abhishek_mumbai Done with GMAT - 700 Join Date: Apr 2009 Location: Pune, India Posts: 1,182	I don't see where you are wrong.. you take 2 inside the (x+y) and your answer will be same as OE..

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