Question:
If one root of the equation x2 + px + 12 = 0 is 4, then the sum of the roots is ____________.
Solution:
One root of $x^{2}+p x+12=0$ is 4
Let us suppose the other solution is $z$.
$\therefore$ Sum of roots $=\frac{-p}{1}=-p$
i. e. $z+4=-p$
and product of roots is 12
i. e. $4 z=12$
i. e. $z=3$
$\Rightarrow$ sum of roots is $4+3=7$