Answer:
see below
Step-by-step explanation:
[tex] \sqrt{64} + \sqrt{-144} = \sqrt{8^2} + \sqrt{-1 \times 12^2} [/tex]
[tex] ~~~~~~~~ = 8 + i \times \sqrt{12^2} [/tex]
[tex] ~~~~~~~~ = 8 + 12i [/tex]