Question

x+ $\frac{1}{x}$ =3
Calculati $x^{2}$+$\frac{1}{ x^{2} }$

Answer 1

daca x+$\frac{1}{x}$=3    |*x
 atunci x² +1=3x
x²=3x-1

x²+$\frac{1}{ x^{2} }$ =

  =  3x-1+ $\frac{1}{3x-1}$  =  $\frac{(3x-1)(3x-1)+1}{(3x-1)}$= 

=$\frac{9 x^{2} -6x+1+1}{(3x-1)}$=

=$\frac{9*(3x-1)-6x+2}{(3x-1)}$=

=$\frac{27x-9-6x+2}{(3x-1)}$=

=$\frac{21x-7}{(3x-1)}$  =  $\frac{7*(3x-1)}{(3x-1)}$    =  7

Answer 2

RAspunsu este 7 restu rezolva