Vimala was asked to simplify the expression \(3a(4a^{4} - 2a + 9)\).
She wrote the result as \(12a^{4} - 6a + 27a\)
However, her teacher marked her answer incorrect.
Based on the situation, answer the following questions.
1. What should be the correct expansion of \(3a(4a^{4} - 2a + 9)\)?
2. What error did Nilan make while multiplying the expressions?
3. Which rule of exponents should he use to rectify his mistake?
4. What is the degree of the correct expansion?