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Calculon

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This is an interesting question I found, it took me a while to figure out and I thought some of you might be up for a challenge

Express 4x<sup>2</sup> + 4x + 9y<sup>2</sup> - 6y - 3 - 12xy as the product of two factors
 

Euler

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there is a perfect square screaming out. once you have that, it falls out nicely.
 

Affinity

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I usually tackle it by .. let y = 0, then let x=0 then ... :D
 

KeypadSDM

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Originally posted by Calculon
Express 4x<sup>2</sup> + 4x + 9y<sup>2</sup> - 6y - 3 - 12xy as the product of two factors
Euler was right. It makes it dead simple:

4x<sup>2</sup> + 4x + 9y<sup>2</sup> - 6y - 3 - 12xy
= 4x<sup>2</sup> - 12xy + 9y<sup>2</sup> + 4x - 6y - 3
= (2x - 3y)<sup>2</sup> + 2(2x - 3y) - 3

Note, - 3 = 3 * -1
3 - 1 = 2
 

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