Question

Simplify.
(2+i)(2-i)(4+3i)

Answer 1

\[20+15i\]

Answer 2

5(4+3i)
=20+15i

Answer 3

start with the fact that
\[(a+bi)(a-bi)=a^2+b^2\] so rewrite this as
\[5(4+3i)\]

Answer 4

(2+i)(2-i)=2^2-i^2... but after that... quite clueless... is this how to start off?

Answer 5

i gotta wonder what constitutes a simplification ...