Question

If $a^2-5a-1=0$ and $a\ne 0$, find $a–\frac{1}{a}$.

• A. 5
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is A 5

Given, $a^2-5a-1=0$
Rewriting the equation, we get
$a^2-1=5a$
$\frac{(a^2-1)}{a}=5$
Hence, $a-\frac{1}{a}=5$