1: =(x-y)(x+y)-2(x+y)
=(x+y)(x-y-2)
3: \(=3\left(4x^2+4x+1-y^2\right)=3\left(2x+1-y\right)\left(2x+1+y\right)\)
5: \(=\left(x^2-1\right)\left(x^2-4\right)=\left(x-1\right)\left(x+1\right)\left(x-2\right)\left(x+2\right)\)
7: \(=\left(x^2+3x\right)\left(x^2+3x+2\right)+1\)
\(=\left(x^2+3x+1\right)^2\)
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1: (x-y)(x+y)-2(x+y) = ( x=y) ( x-y-2)
3: 3(4x2+4x+1−y2)=3(2x+1−y)(2x+1+y)
5: (x2−1)(x2−4)=(x−1)(x+1)(x−2)(x+2)
7: (x2+3x)(x2+3x+2)+1=(x2+3x)(x2+3x+2)+1 = ( x2+3x+1)2
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