Multiplying/dividing complex numbers.
Write in the form of a + bi:

a) (6-√(-27))(5+√(-12)

b) (7+4i)^2

c) (5+3i)(5-3i)

d) 4/(5-2i)

e) (2+3i)/(2-3i)

f) 2/(5+√(-16))

Thank you!