Answer
Two solutions
Work Step by Step
$$ \text{The quadratic formula is given by:}$$ $$ x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}$$
$$ \text{Plugging in the given values:}$$
$$a=1, b=0, c=-15$$
$$ x = \frac{-0 \pm \sqrt{0^2-4(1)(-15)}}{2(1)}$$
$$\text{Reducing within the radical gives: } $$
$$ x = \frac{-0 \pm \sqrt{60}}{(2)1}$$
$$ \text {This gives: } $$
$$x=3.87298334620742,-3.87298334620742$$