Find the product of (6+3i) (4-2i).

(6+3i) (4-2i)

= 24 -12i + 12i - 6i^2 , but i^2 = -1
= 24 -6(-1)
= 24 + 6 = 30

or

3(2+i)(2)(2-i)
= 6(4 - i^2)
= 6(4 + 1) = 30