Respostas

2014-08-30T13:16:02-03:00
A)
(5-3i)-(2+5i) = 3-8i

b) 
(2+5i)-(7-2i) = -5+7i

c)
(7-2i)*(5-3i) =
35-21i-10i+6i² =
35-31i+6.(-1) =
35-6-31i =
29-31i