Simplify expressions Math help please. Show me how so i can do it.

a) (3-4i)(6+5i)


b) (7+2i) / (3-5i)


Thank you for your genius

a) 18 + 15i -24i + 20 (the 20 is positive because i^2 = -1)
38 - 9i

b) Multiply top and bottom by (3 + 5i)
(7 + 2i)(3 + 5i)/ (3 + 5i)(3 - 5i)
(21 +35i + 6i -15)/( 9 +25)
(6 + 41i)/34