How do you simplify #(3-4i)(-1+2i)#?

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Answer 1 · 2015-12-25T03:53:52

#5+10i#

Use the FOIL method of distribution.

#(3-4i)(-1+2i)#

#=>3(-1)+3(2i)-4i(-1)-4i(2i)#

#=>-3+6i+4i-8i^2#

#=>-3+10i-8i^2#

Now, recall that #i^2=-1#. This is true since #i=sqrt(-1)#.

#=>-3+10i-8(-1)#

#=>-3+10i+8#

#=>5+10i#