Answer
$-5+10i$.
Work Step by Step
The given expression is
$=(2+i)^2-(3-i)^2$
Use the special formula $(A+B)^2=A^2+2AB+B^2$
We have $A=(2+i)$ and $B=(3-i)$.
$=[(2+i)-(3-i)][(2+i)+(3-i)]$
Clear the parentheses.
$=[2+i-3+i][2+i+3-i]$
Add like terms.
$=[-1+2i][5]$
Use the distributive property.
$=-5+10i$.
