Roots of Quadratic Equation – Example

Remember : Roots of a quadratic equation are the values of variables/unknowns that satisfy the equation.

Example
(a) Given x = 3 is the root of the quadratic equation $x^2+2x+p=0$ , find the value of p.
(b) The roots of the quadratic equation $3x^2+hx+k=0$   are -2 and 4. Find the value of h and k.