Answer
$x^2 + 8x + 15 = 0$
boundary points
Work Step by Step
Polynomial inequalities are solved by setting the function $f(x)=0$. Thus, the equation $x^2 + 8x + 15 = 0$ must first be solved.
The real solutions of this equation, $-5$ and $-3$, shown on the number line, are called boundary points.