Question

If one root of the equation $x^2+px+12=0$ is $4$, then the sum of the roots is

Answer 1

Given: $4$ is one root of the equation

$x^2+px+12=0$

$\Rightarrow 4^2+p\left(4\right)+12=0$

$\Rightarrow 4p+28=0$

$\Rightarrow p=-7$

Now,

$\text{Sum of roots}=-\frac{\text{coefficient of}x}{\text{coefficient of}{x}^2}$

$\Rightarrow$Sum of roots $=-\frac{p}{1}=7$