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Calculati x²+1/x²,stiind can x-1/x=3

Răspuns :

(x-1/x)^2=3^2 x^2-2x1/x+1/x^2=9|-2x1/x x^2+1/x^2=7
rezolvam intai a doua ecuatia x-1/x=3
3x=x-1
2x=-1
x=-1/2
[tex] x^{2} + \frac{1}{ x^{2} } = \frac{1}{4} + \frac{1}{ \frac{1}{4} } = \frac{1}{4} +4[/tex]= [tex] \frac{17}{4} [/tex]