Respuesta :

the answer is 80 take the positive and negative and use the sign change rule

Answer:

50

Step-by-step explanation:

First, find the square roots.

[tex]\sqrt{-16} =4i[/tex]

[tex]\sqrt{-64} =8i[/tex]

Remember: i stands for [tex]\sqrt{-1}[/tex]

Then use the FOIL method to multiply.

(3+4i)(6-8i)

18-24i+24i-32i²

i²= -1, so :

18+32

50

I have no idea what the other person did, but its wrong.