Answer:
-30a^5*b+12a^4b^2+6a^3b^2+10a^3b^2-4a^2b^3-2ab^3
The product is (-30a^5.b+12a^4.b^3+16a^3.b^2-4a^2.b^4-2ab^3)
Step by step process is above.