Question

Se k+i/i = 1-3i então K vale:

a)3
b)-3
c)5
d)-5

Answer 1

k+i = 1-3i
   i

-i(k+i) = 1-3i
   i(-i)

-ik - i²  = 1-3i
   -i²

-ik - (-1)  = 1-3i  ==> -ik + 1 = 1 - 3i
   -(-1)                            1                  

-ik + 1 = 1 - 3i ==>  -ik + 3i = 1 - 1

-ik + 3i = 0  
 
ik = 3i

k = 3i ==> k = 3
       i

letra A