How do you multiply (6-3i)(3-i)?

1 Answer
Sep 12, 2016

15-15i

Explanation:

distribute the brackets using, for example, the FOIL method.

rArr(6-3i)(3-i)=18-6i-9i+3i^2=18-15i+3i^2

color(orange)"Reminder "

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

rArr18-15i+3i^2=18-15i-3=15-15i

rArr(6-3i)(3-i)=15-15i