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Question-76307




Question Number 76307 by Master last updated on 26/Dec/19
Answered by mr W last updated on 26/Dec/19
x≠1  125(1+x^5 )=11(1+x)^5   125(1−x+x^2 −x^3 +x^4 )=11(1+x)^4   114x^4 −169x^3 +59x^2 −169x+114=0  (3x−2)(2x−3)(19x^2 +13x+19)=0  ⇒x_1 =(2/3)  ⇒x_2 =(3/2)  ⇒x_(3,4) =((−13±i5(√(51)))/(38))
$${x}\neq\mathrm{1} \\ $$$$\mathrm{125}\left(\mathrm{1}+{x}^{\mathrm{5}} \right)=\mathrm{11}\left(\mathrm{1}+{x}\right)^{\mathrm{5}} \\ $$$$\mathrm{125}\left(\mathrm{1}−{x}+{x}^{\mathrm{2}} −{x}^{\mathrm{3}} +{x}^{\mathrm{4}} \right)=\mathrm{11}\left(\mathrm{1}+{x}\right)^{\mathrm{4}} \\ $$$$\mathrm{114}{x}^{\mathrm{4}} −\mathrm{169}{x}^{\mathrm{3}} +\mathrm{59}{x}^{\mathrm{2}} −\mathrm{169}{x}+\mathrm{114}=\mathrm{0} \\ $$$$\left(\mathrm{3}{x}−\mathrm{2}\right)\left(\mathrm{2}{x}−\mathrm{3}\right)\left(\mathrm{19}{x}^{\mathrm{2}} +\mathrm{13}{x}+\mathrm{19}\right)=\mathrm{0} \\ $$$$\Rightarrow{x}_{\mathrm{1}} =\frac{\mathrm{2}}{\mathrm{3}} \\ $$$$\Rightarrow{x}_{\mathrm{2}} =\frac{\mathrm{3}}{\mathrm{2}} \\ $$$$\Rightarrow{x}_{\mathrm{3},\mathrm{4}} =\frac{−\mathrm{13}\pm{i}\mathrm{5}\sqrt{\mathrm{51}}}{\mathrm{38}} \\ $$
Commented by Master last updated on 26/Dec/19
sir  125(1+x^5 )=11(1+x)^5   125(((1+x^5 ))/((1+x)))=11(1+x)^4  ⇔ (1−x+x^2 −x^3 +x^4 ) ???
$$\mathrm{sir}\:\:\mathrm{125}\left(\mathrm{1}+\mathrm{x}^{\mathrm{5}} \right)=\mathrm{11}\left(\mathrm{1}+\mathrm{x}\right)^{\mathrm{5}} \\ $$$$\mathrm{125}\frac{\left(\mathrm{1}+\mathrm{x}^{\mathrm{5}} \right)}{\left(\mathrm{1}+\mathrm{x}\right)}=\mathrm{11}\left(\mathrm{1}+\mathrm{x}\right)^{\mathrm{4}} \:\Leftrightarrow\:\left(\mathrm{1}−\mathrm{x}+\mathrm{x}^{\mathrm{2}} −\mathrm{x}^{\mathrm{3}} +\mathrm{x}^{\mathrm{4}} \right)\:??? \\ $$
Commented by john santuy last updated on 26/Dec/19
(1+x)^5 =1+5x+10x^2 +10x^3 +5x^4 +x^5   1+x^5  =(1+x)^5 −5x−10x^2 −10x^3 −x^4
$$\left(\mathrm{1}+{x}\right)^{\mathrm{5}} =\mathrm{1}+\mathrm{5}{x}+\mathrm{10}{x}^{\mathrm{2}} +\mathrm{10}{x}^{\mathrm{3}} +\mathrm{5}{x}^{\mathrm{4}} +{x}^{\mathrm{5}} \\ $$$$\mathrm{1}+{x}^{\mathrm{5}} \:=\left(\mathrm{1}+{x}\right)^{\mathrm{5}} −\mathrm{5}{x}−\mathrm{10}{x}^{\mathrm{2}} −\mathrm{10}{x}^{\mathrm{3}} −{x}^{\mathrm{4}} \\ $$
Commented by mr W last updated on 26/Dec/19
is it a question sir? can you please  use more words to make clear  what you mean instead of  letting  guess? thank you!
$${is}\:{it}\:{a}\:{question}\:{sir}?\:{can}\:{you}\:{please} \\ $$$${use}\:{more}\:{words}\:{to}\:{make}\:{clear} \\ $$$${what}\:{you}\:{mean}\:{instead}\:{of}\:\:{letting} \\ $$$${guess}?\:{thank}\:{you}! \\ $$
Commented by Master last updated on 26/Dec/19
thanks
$$\mathrm{thanks} \\ $$
Commented by mr W last updated on 26/Dec/19
1+x^5 =(1+x)(1−x+x^2 −x^3 +x^4 )
$$\mathrm{1}+{x}^{\mathrm{5}} =\left(\mathrm{1}+{x}\right)\left(\mathrm{1}−{x}+{x}^{\mathrm{2}} −{x}^{\mathrm{3}} +{x}^{\mathrm{4}} \right) \\ $$

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