Step-by-step explanation:
(5−4i)(2+9i)
=(5+−4i)(2+9i)
=(5)(2)+(5)(9i)+(−4i)(2)+(−4i)(9i)
=10+45i−8x−36i2
=−36i2+37i+10
Answer:
D.) 46 + 37i
(5 - 4i)(2 + 9i)
use the FOIL method
10 + 45i - 8i + 36
collect like terms
(10 + 36) + (45i - 8i)
simplify
46 + 37i
