Alright, let get started.
[tex] (\sqrt{-49})^{3} [/tex]
49 could be written as [tex] 7^{2} [/tex], it means
[tex] (\sqrt{-7^{2}})^{3} [/tex]
[tex] (7\sqrt{-1})^{3} [/tex]
[tex] \sqrt{-1} [/tex] could be written as i
[tex] (7i)^{3} [/tex]
[tex] 343i^{3} [/tex]
[tex] 343i^{2} i [/tex]
As we know, [tex] i^{2} = -1 [/tex]
[tex] -343 i [/tex]
That is the answer:
Hope it will help :)
