Answer:
[tex]-18-6i[/tex]
Step-by-step explanation:
[tex](3i)(2+4i)-2(3+6i)[/tex]
[tex](3i)(2)+(3i)(4i)+(-2)(3)+(-2)(6i)[/tex]
[tex]6i+12i^2-6-12i[/tex] (remember that [tex]i^2=-1[/tex])
[tex]-6i+12(-1)-6[/tex]
[tex]-6i-12-6[/tex]
[tex]-6i-18[/tex]
[tex]-18-6i[/tex]
