Answer
-15
Work Step by Step
We know that $i=\sqrt{-1}$ and that $i^2=-1$. We also know that standard form is $a\pm bi$, where a and b are real numbers. Thus, simplifying the equation, we find:
$$ \sqrt{15}i\cdot \sqrt{15}i \\ \\ -\sqrt{225} \\ -15$$
