a) 9x3 - 27x2 =0;

To solve the equation \(9x^3 - 27x^2 = 0\), we will first factor out the common terms.

1. Factor out the common term: \[ 9x^2(x - 3) = 0 \]

2. Set each factor equal to zero:

   • From \(9x^2 = 0\): \[ x^2 = 0 \implies x = 0 \]
   • From \(x - 3 = 0\): \[ x = 3 \]

3. Thus, the solutions to the equation \(9x^3 - 27x^2 = 0\) are: \[ x = 0 \quad \text{and} \quad x = 3 \]

The final answers are \(x = 0\) and \(x = 3\).