Question

ultimul exercitiu cum se face?

Answer 1

(x+$\frac{1}{x}$=3)²
x²+2x*$\frac{1}{x}$+$\frac{1}{ x^{2} }$=9
x se reduce si atunci ==> x²+2+$\frac{1}{ x^{2} }$=9
x²+$\frac{1}{ x^{2} }$=9-2
x²+$\frac{1}{ x^{2} }$=7