Question

If one of the roots of the quadratic equation $x^2-11x+k=0$ is $9$, then find the value of $k$.

Answer 1

Given quadratic equations is $x^2-11x+k=0$ ....... $\left(i\right)$

One of the roots of the given quadratic equation $9$

So, $x=9$ will satisfy $\left(i\right)$

$\Rightarrow 9^2$$-11\times 9$$+k$$=0$

$\Rightarrow 81-99+k=0$

$\Rightarrow k=18$