Question

Imi puteti va rog rezolva pb 4 din poza? .. Va multumesc :D

Answer 1

(x+1/x)^2=x^2+1/x^2+2=16, R=16-2=14, (2x/x=2)

Answer 2

$x+ \frac{1}{x}=4 \ \ \ |^2 \\\\ (x+\frac{1}{x})^2=16 \\\\\\ x^2+ 2* \not x * \frac{1}{\not x}+ \frac{1}{x^2}=16 \\\\ x^2+\frac{1}{x^2}+2=16 \ \ \ |(-2)\\\\\\ \boxed{x^2+\frac{1}{x^2}=14}$