Answer and Step-by-step explanation:
To simplify the expression 4a(5a^(2)-4)+9a, we can start by distributing the 4a to the terms inside the parentheses. This gives us 20a^(3)-16a+9a. Combining like terms, we get 20a^(3)-7a. So, the simplified form of the expression is 20a^(3)-7a.