Răspuns :

x + 1 / x = 2

x² + 1 = 2x => x² - 2x = 1

x² - 2x - 1 = 0

a = 1

b = - 2

c = - 1

Delta = b² - 4ac

D = - 2² - 4 * 1 * ( - 1 )

D = 4 - 4 * ( - 1 )

D = 4 + 4

D = 8

X1 = ( - b - rad. D ) / 2a

X1 = 2 - 2 rad. 2 / 2 * 1

X1 = 2 - 2 rad. 2 / 2

X1 = 2 - rad. 2

X2 = ( - b + rad. D ) / 2a

X2 = 2 + 2 rad. 2 / 2 * 1

X2 = 2 + 2 rad. 2 / 2

X2 = 2 + rad. 2

Răspuns:

[tex]x + \frac{1}{x} = 2 \\x + \frac{1}{x} - 2 = 0 \\ \frac{ {x}^{2} + 1 - 2x}{x} =0 \\ \frac{ {(x - 1)}^{2} }{x} = 0[/tex]

Raportul dintre doua numere e 0 numai si numai daca numaratorul e 0.

Deci

[tex] {(x - 1)}^{2} = 0 \\ |x - 1| = 0 \\ x - 1 = 0 \\ x = 1[/tex]