Performing Arithmetic with Complex Numbers

We want to simplify the given numeric expression using the imaginary unit, $i.$ To do so, we will first recall that the imaginary unit $i$ is the complex number whose square is $\text{-}1.$ $$i^2=\text{-}1\text{and}i=\sqrt{\text{-}1}$$ We can simplify the expression using this definition.