How do you multiply #5(-i)(-4+6i)#?

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Answer 1 · 2018-08-10T17:43:38

#30 + 20i#

#5(-i)(-4+6i)#

#-5i(-4+6i)#

Distribute the #-5i#:
#20i - 30i^2#

We know that #i^2 = -1#, so:
#20 i - 30(-1)#

#20i + 30#

Rewrite in standard form:
#30 + 20i#

Hope this helps!