Question

I think I have the right answer but I just want to check.

Answer 1

Expand the parenthesis using the distributive property twice:

`\begin{gathered} (3+4i)(3-4i)=(3+4i)\cdot3+(3+4i)\cdot-4i \\ =3\cdot3+4i\cdot3+3\cdot-4i+4i\cdot-4i \\ =9+12i-12i-16i^2 \\ =9-16(-1) \\ =9+16 \\ =25 \end{gathered}`

Therefore, the answer is:

`25`