Can someone explain how I would solve this?
Find the product of the number and its conjugate.
square root of negative 15.
The product of a complex number and its conjugate is equal to the square of the modulus of the complex number.
Here,
complex number is $\displaystyle \sqrt{-15}$ or $\displaystyle i\sqrt{15}$
What is the modulus of this number?
What is conjugate of this number?