How do you simplify #-6i(8-6i)(-8-8i)#?

1 Answer
Sep 9, 2016

#-96+672i#

Explanation:

Before multiplying by - 6i , expand the brackets, using for example, the FOIL method.

#rArr(8-6i)(-8-8i)=-64-64i+48i+48i^2#

#color(orange)"Reminder " color(red)(bar(ul(|color(white)(a/a)color(black)(i^2=(sqrt(-1))^2=-1)color(white)(a/a)|)))#

#rArr(8-6i)(-8-8i)=-16i-112#

and #-6i(-16i-112)=96i^2+672i=-96+672i#