Question

daca x+ 1 supra x =7 ,calculati x la a 2 a +1 supra x la a doua

Answer 1

$\frac{x + 1}{x} = 7$

$\frac{x}{x} + \frac{1}{x} = 7$

$1 + \frac{1}{x} = 7 \: | - 1$

$\frac{1}{x} = 6 \: = > x = \frac{1}{6}$

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

$= 1 + \frac{1}{( { \frac{1}{6}) }^{2} } = 1 + \frac{1}{ \frac{1}{36} } = 1 + 36 =$

$= 37$

Answer 2

Răspuns:

Explicație pas cu pas:

x + 1/x = 7

( x + 1/x )² - 2 x × ( 1/x) = 7² - 2 = 49 - 2 = 47

x² + 1/x² = 47