How do you simplify #(4-5i)(4+i)#?
1 Answer
Nov 1, 2016
Explanation:
Distribute the brackets using, for example, the FOIL method.
#(4-5i)(4+i)=16+4i-20i-5i^2=16-16i-5i^2#
#color(orange)"Reminder " color(red)(bar(ul(|color(white)(2/2)color(black)(i^2=(sqrt(-1))^2=-1)color(white)(2/2)|)))#
#rArr16-16i-5i^2=16-16i+5=21-16i#
