For #i=sqrt(-1)# is the sum of #(7+3i) + (-8+9i)#?

1 Answer
Jun 8, 2016

#12i-1#

Explanation:

#7+3i +(-8+9i)#

First, open up the bracket:

#=7+3i -8+9i#

Next, combine the numbers and #i# terms:

#=color(red)7color(blue)(+3i) color(red)(-8)color(blue)(+9i)#

#=color(red)(7-8)+color(blue)(3i+9i)#

#=color(red)(-1)+color(blue)(12i)#

#=12i-1#