Answer:
Step-by-step explanation:
(5y+4+3x)(5y+4-3x) = (5y+4)² - (3x)²......(from the difference of 2 squares )
by identity : (a+b)(a-b) = a² - b²
in this exercice ; a = 5y+4 and b = 3x
Answer: 
Step-by-step explanation:

if it matters then simply further...
4 + \sqrt{4i} = 