How to get answer:
[tex]((-2a^2)(b))(9a^5b^3-4ab^5)[/tex]
[tex]=((-2a^2)(b))(9a^5b^3+-4ab^5)[/tex]
[tex]=((-2a^2)(b))(9a^5b^3)+((-2a^2)(b))(-4ab^5)[/tex]
Answer: [tex]=-18a^7b^4+8a^3b^6[/tex]
