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Question-145113




Question Number 145113 by imjagoll last updated on 02/Jul/21
Answered by liberty last updated on 02/Jul/21
⇒5(x^4 +x^2 +1−2x^3 +2x^2 −2x)=(9x^2 +9)(x^2 −2x+1)  ⇒5x^4 −10x^3 +15x^2 −10x+5=       9x^4 −18x^3 +18x^2 −18x+9  ⇒4x^4 −8x^3 +3x^2 −8x+4= 0  ⇒(x−2)(4x^3 +3x−2)=0  ⇒x=2(solution)  ⇒4x^3 +3x−2=0  ⇒(2x−1)(2x^2 +x+2)=0  ⇒x=(1/2)(solution)  ⇒2x^2 +x+2=0  ⇒x = ((−1 ± (√(1−16)))/4) = ((−1±i(√(15)))/4)(not solution)
$$\Rightarrow\mathrm{5}\left({x}^{\mathrm{4}} +{x}^{\mathrm{2}} +\mathrm{1}−\mathrm{2}{x}^{\mathrm{3}} +\mathrm{2}{x}^{\mathrm{2}} −\mathrm{2}{x}\right)=\left(\mathrm{9}{x}^{\mathrm{2}} +\mathrm{9}\right)\left({x}^{\mathrm{2}} −\mathrm{2}{x}+\mathrm{1}\right) \\ $$$$\Rightarrow\mathrm{5}{x}^{\mathrm{4}} −\mathrm{10}{x}^{\mathrm{3}} +\mathrm{15}{x}^{\mathrm{2}} −\mathrm{10}{x}+\mathrm{5}= \\ $$$$\:\:\:\:\:\mathrm{9}{x}^{\mathrm{4}} −\mathrm{18}{x}^{\mathrm{3}} +\mathrm{18}{x}^{\mathrm{2}} −\mathrm{18}{x}+\mathrm{9} \\ $$$$\Rightarrow\mathrm{4}{x}^{\mathrm{4}} −\mathrm{8}{x}^{\mathrm{3}} +\mathrm{3}{x}^{\mathrm{2}} −\mathrm{8}{x}+\mathrm{4}=\:\mathrm{0} \\ $$$$\Rightarrow\left({x}−\mathrm{2}\right)\left(\mathrm{4}{x}^{\mathrm{3}} +\mathrm{3}{x}−\mathrm{2}\right)=\mathrm{0} \\ $$$$\Rightarrow{x}=\mathrm{2}\left({solution}\right) \\ $$$$\Rightarrow\mathrm{4}{x}^{\mathrm{3}} +\mathrm{3}{x}−\mathrm{2}=\mathrm{0} \\ $$$$\Rightarrow\left(\mathrm{2}{x}−\mathrm{1}\right)\left(\mathrm{2}{x}^{\mathrm{2}} +{x}+\mathrm{2}\right)=\mathrm{0} \\ $$$$\Rightarrow{x}=\frac{\mathrm{1}}{\mathrm{2}}\left({solution}\right) \\ $$$$\Rightarrow\mathrm{2}{x}^{\mathrm{2}} +{x}+\mathrm{2}=\mathrm{0} \\ $$$$\Rightarrow{x}\:=\:\frac{−\mathrm{1}\:\pm\:\sqrt{\mathrm{1}−\mathrm{16}}}{\mathrm{4}}\:=\:\frac{−\mathrm{1}\pm{i}\sqrt{\mathrm{15}}}{\mathrm{4}}\left({not}\:{solution}\right) \\ $$
Commented by MJS_new last updated on 02/Jul/21
something went wrong. the answer is  x=(1/2)∨x=2     [∨x=−(1/4)±((√(15))/4)i]
$$\mathrm{something}\:\mathrm{went}\:\mathrm{wrong}.\:\mathrm{the}\:\mathrm{answer}\:\mathrm{is} \\ $$$${x}=\frac{\mathrm{1}}{\mathrm{2}}\vee{x}=\mathrm{2}\:\:\:\:\:\left[\vee{x}=−\frac{\mathrm{1}}{\mathrm{4}}\pm\frac{\sqrt{\mathrm{15}}}{\mathrm{4}}\mathrm{i}\right] \\ $$
Commented by liberty last updated on 02/Jul/21
yes.
$${yes}.\: \\ $$

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