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

Question

6802 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-12-08T03:40:45

#5-i#

Use the FOIL method.

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

#=2-3i+2i-3i^2#

#=2-i-3i^2#

While this may appear to be as simplified as possible, it's not.

Since #i=sqrt(-1)#, it's also true that #i^2=-1#. Because of this, we can replace the #i^2# with #-1#.

#=2-i-3(-1)#

#=2-i+3#

#=5-i#