Question 94467
4x^4-19x^3-5x^2
=x^2[4x^2-19x-5]

= x^2[4x^2-20x+x-5]

= x^2[4x^2(x-5)+(x-5)]

= x^2(4x^2+1)(x-5)

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Cheers,
Stan H.