Question 146082
3i(3+8i) 
distribute the 3i to each term inside the parenthesis:
(3i)(3)+(3i)(8i) 
= (3*3*i) + (3*8*i*i)
= 9i + ((3*8)*(i*i))
= 9i + ((24)*(-1))
= 9i + (-24)
= -24 + 9i