How do you multiply #6i(4-12i)#?
1 Answer
Jul 23, 2016
72 + 24i
Explanation:
#color(blue)"distribute the bracket"# in the usual way. That is, multiply each term inside the bracket by the 6i, outside.
#rArr(6ixx4)-(6ixx12i)=24i-72i^2# and simplify
#color(orange)"Reminder" color(red)(|bar(ul(color(white)(a/a)color(black)(i^2=sqrt((-1)^2)=-1)color(white)(a/a)|)))#
#24i-72i^2=24i-72(-1)=24i+72#
#rArr6i(4-12i)=24i+72#
