Answer:
315 hours
Step-by-step explanation:
Good luck
(1 - 3i)(5 + 5i)(4 - 1i)
= (5 + 5i - 15i - 15i²)(4 - 1i)
= (5 - 10i - 15i²)(4 - 1i)
= 20 - 40i - 60i² - 5i + 10i² + 15i³
= 20 - 45i - 50i² + 15i³