While you could find the prime factors \(399\) and determine that the two roots are \(19\) and \(21\), there is a quadratic pattern that we can use to answer this question.

The quadratic equation is given by the general form:

\(ax^2\)+

\(bx\)+

\(c\)\(=0\), where:

\(a =\) coefficient of \(x^2\)\(b =\) coefficient of \(x\)\(c =\) constant A quadratic equation can have two roots and the sum of its roots is given by

\(-b\) /

\(a\), therefore:

\(sum \ of \ roots = -\frac{b}{a} = - \frac{(-40)}{1} = 40\)

The final answer is

.