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Find-an-integer-x-that-satisfies-the-equation-x-5-101x-3-999x-2-100900-0-




Question Number 8707 by Sopheak last updated on 22/Oct/16
Find an integer x that satisfies the equation   x^5 −101x^3 −999x^2 +100900=0
Findanintegerxthatsatisfiestheequationx5101x3999x2+100900=0
Answered by Rasheed Soomro last updated on 23/Oct/16
The solution is factor of 100900.  So on trying x=10 is one solution.  That also means that x−10 is a factor  of  x^5 −101x^3 −999x^2 +100900  By synthetic division we can determine  other factor:   determinant (((10)),1,0,(−101),(−999),0,(+100900)),(,,(10),(+100),(−10),(−10090),(−100900)),(,1,(10),(−1),(−1009),(−10090),([      0)))  So the other factor is           x^4 +10x^3 −x^2 −1009x−10090  The rest roots of the given equation are the  roots of   x^4 +10x^3 −x^2 −1009x−10090=0  Trying all the possible integer factors of 10090  we learn that there is no other integer solution.  So x=10
Thesolutionisfactorof100900.Soontryingx=10isonesolution.Thatalsomeansthatx10isafactorofx5101x3999x2+100900Bysyntheticdivisionwecandetermineotherfactor:|10)101019990+10090010+10010100901009001101100910090[0|Sotheotherfactorisx4+10x3x21009x10090Therestrootsofthegivenequationaretherootsofx4+10x3x21009x10090=0Tryingallthepossibleintegerfactorsof10090welearnthatthereisnootherintegersolution.Sox=10

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