Question

In the given equation, find the negative value of p.
$p-3=\frac{10}{p}$

• A. $-2$
• B. $-5$
• C. $-10$
• D. None

Answer 1

Answer: (A)

$-2$

$p-3=\frac{10}{p}$

$p^2-3p=10p$

$p^2-3p-10=0$

Here, $a=1,b=-3,c=-10$ by comparing with the general quadratic equation $a{x}^2+bx+c$.

Using quadratic formula we get,

$p=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$p=\frac{-(-3)\pm \sqrt{(-3{)}^2-4\times 1\times (-10)}}{2}$

$p=\frac{+3\pm \sqrt{9+40}}{2}$

$p=\frac{3\pm 7}{2}$

$p=\frac{3+7}{2}=5$

and $p=\frac{3-7}{2}=-2$

Therefore the negative value of $p=-2$.