_nhanh giúp mình nhaa

1) `x^2 - y^2 -2x+2y`

`= (x^2 -y^2)-(2x-2y)`

`= (x+y)(x-y)-2(x-y)`

`= (x+y-2)(x-y)`

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2) `(2x+2y)-x^2 -xy`

`= (2x+2y)-(x^2 +xy)`

`= 2(x+y)-x(x+y)`

`= (2-x)(x+y)`

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3) `x^2 -25+y^2 +2xy`

`= (x^2 +2xy+y^2)-25`

`= (x+y)^2 - 5^2`

`= (x+y-5)(x+y+5)`

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4) `x^2 -2x-4y^2 -4y`

`= (x^2 -4y^2)-(2x+4y)`

`= [x^2 - (2y)^2] - (2.x+2.2y)`

`= (x-2y)(x+2y)-2(x+2y)`

`= (x-2y-2)(x+2y)`

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5) `x^2 y-x^3 -9y+9x`

`= (x^2 y-x^3) -(9y-9x)`

`= x^2 (y-x) -9(y-x)`

`= (x^2 -9)(y-x)`

`= (x^2 -3^2)(y-x)`

`= (x+3)(x-3)(y-x)`

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6) `x^2 (x-1) + 16(1-x)`

`= x^2 (x-1) -16(x-1)`

`= (x^2 -16)(x-1)`

`= (x^2 -4^2)(x-1)`

`= (x-4)(x+4)(x-1)`