Respuesta :
(x^2+x+4)(x-4)
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= (x^2+x+4)x - (x^2+x+4)4
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= x^3+x^2+4x -4x^2-4x-16
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= x^3-3x^2+16
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Add:
(8x^2-xy+y^2)+(-x^2-4xy+6y^2
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= 7x^2-5xy+7y^2
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---
= (x^2+x+4)x - (x^2+x+4)4
-----
= x^3+x^2+4x -4x^2-4x-16
---
= x^3-3x^2+16
----------------------
Add:
(8x^2-xy+y^2)+(-x^2-4xy+6y^2
---
= 7x^2-5xy+7y^2
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