Answer :
18. Is D 19. Is B
Hope this helps
Explanation
So for 18 you use FOIL
(6+5i)(3-7i)
18-42i+15i-35i^2 i^2=-1
18-27i-(35)(-1)
substitute -1 in and add like terms
53-27i
Then for 19
(1-14i)(5-3i)
5-3i-70i+42i^2
5-73i+(42)(-1)
-37-73i
Hope this helps
Explanation
So for 18 you use FOIL
(6+5i)(3-7i)
18-42i+15i-35i^2 i^2=-1
18-27i-(35)(-1)
substitute -1 in and add like terms
53-27i
Then for 19
(1-14i)(5-3i)
5-3i-70i+42i^2
5-73i+(42)(-1)
-37-73i