Question

a+1/a=5 then a²+1/a²​

Answer 1

$1 + \frac{1}{a} = 5 \\ squaring \: both \: sides \\ 1 + \frac{1}{ {a}^{2} } + \frac{2}{a} = 25 \\ \\ \frac{ {a}^{2} + 1 }{ {a}^{2} } = \frac{25a - 2}{a}$