1.x(x-y)+y(y-x)2.9(a-b)^2-16(a+b)^2 3.25(x-y)^2+10(y-x)+1

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1.x(x-y)+y(y-x)2.9(a-b)^2-16(a+b)^2 3.25(x-y)^2+10(y-x)+1
1.x(x-y)+y(y-x)2.9(a-b)^2-16(a+b)^2 3.25(x-y)^2+10(y-x)+1

1.x(x-y)+y(y-x)2.9(a-b)^2-16(a+b)^2 3.25(x-y)^2+10(y-x)+1
1 9(a-b)^2-16(a+b)^2
=-7a^2-50ab-7b^2
=-(7a+b)(a+7b)
2 3x^3-12x^2y+12xy^2
=3x(x^2-4xy+4y^2)
=3x(x-2y)^2
3 25(x-y)^2+10(y-x)+1
=25(x-y)^2-10(x-y)+1
=[5(x-y)-1]^2
=(5x-5y-1)^2