Question

7. If x-1/x = 5, then the value of x²+1/x' equals to *
(1 Point)
13
17
25
27​

Answer 1

$\frac{x - 1}{x} = 5 \\ \\ x - 1 = 5x \\ 5x - x = - 1 \\ 4x = - 1 \\ x = \frac{ - 1}{4}$

$\frac{ {x}^{2} + 1}{ {x}^{2} } \\ \\ = \frac{ { (\frac{ - 1}{4} )}^{2} + 1 }{ { (\frac{ - 1}{4} )}^{2} } \\ \\ = \frac{ \frac{1}{16} + 1 }{ \frac{1}{16} } \\ \\ = \frac{ \frac{1 + 16}{ \not16} }{ \frac{1}{ \not16} } \\ \\ = \frac{17}{1} \\ \\ = 17$

Option B) 17