Answer:
-1 + 18i
Step-by-step explanation:
⟺ Distribute 3i and i in the expressions.
[tex]12i-i^2+6i+2i^2\\i^2+18i[/tex]
⟺ The define of complex number is
[tex]i^2=-1[/tex]
Thus, convert i² to -1
[tex]-1+18i[/tex]
