Express in the form bi
\(\sqrt{(-4)}\)
\begin{align} \sqrt{4 \; \times -1}\\ & = 2 \sqrt{-1}\\ & = 2i \end{align}
\( 2 \sqrt{(-121)}\)
\begin{align}2 \sqrt{121 \; \times -1}\\ & = 2 \; \times 11 \sqrt{-1}\\ & = 22i \end{align}
\(\sqrt{(-45)}\)
\begin{align} \sqrt{9 \; \times 5 \; \times -1}\\ & = 3 \sqrt{5} \sqrt{-1}\\ & = 3i \sqrt{5} \end{align}
\(i\sqrt{(-49)} \times \sqrt{(-144)}\)
\begin{align} & = i \sqrt{49 \; \times -1} \; \times \sqrt{144 \; \times -1}\\ & = 7i \sqrt{-1} \; \times \; 12 \sqrt{-1}\\ & = 7i^2 \; \times 12i \\ & = -7 \; \times 12i \\ & = -84i \end{align}