Question

please find value of this

Answer 1

Hey !!
Check the attachment.

Answer 2

Hey there !!
we are given
$a - \frac{1}{a} = 4 \\ = > ({a - \frac{1}{a} }^{2} ) = {4}^{2} (squaring \: both \: side) \\ = > ( {a + \frac{1}{a} }^{2}) - 2a \times \frac{1}{a} = 16 \\ = > {a}^{2} + \frac{1}{a} = 18$
Hope this helps u !!
Aishwary ☆BRAINLY STAR ☆